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Core 2 Quad and Duo Temperature Guide
Section 1: Introduction
The purpose of this Guide is to provide users with an understanding of thermal relationships, so that C2Q and C2D temperatures can be uniformly tested, accurately calibrated, and properly monitored. This Guide requires basic familiarity with computer terminology and BIOS menus, but does not require knowledge of unnecessarily diverse or complex technical details. Certain strict definitions have therefore been relaxed to simplify concepts and enhance comprehension.
Intel provides separate thermal specifications for 2 different sensor types; a single Case Thermal Diode located within the CPU die between the Cores, and Digital Thermal Sensors located within each Core. The Case Thermal Diode measures Tcase (Temperature Case), which is commonly known as CPU temp, and the Digital Thermal Sensors measure Tjunction (Temperature Junction), which is commonly known as Core temp. Since these sensors measure 2 distinct thermal levels, there is a constant temperature difference between them, which is referred to as Tcase to Tjunction Delta. C2Q’s have 1 Tcase and 4 Tjunction sensors, while C2D’s have 1 Tcase and 2 Tjunction sensors.
Intel does not provide information which correlates Tcase and Tjunction specifications to normal temperatures and Deltas. Consequently, there is much confusion among users regarding temperature monitoring, software utilities, test methods, Calibrations and Offsets, so Results can be difficult to decipher and compare. When listing Idle & Load test Results, it is also necessary to list the Variables as shown below:
Results and Variables
Tcase = Idle & Load
Tjunction = Idle & Load, hottest Core
Ambient = Room Temp
Chipset = Model
C2Q / C2D = Model
CPU Cooler = Model
Frequency = CPU Clock
Load = Test Program
Motherboard = Model
Stepping = Revision
Vcore = CPU Voltage
Section 2: Specifications
CPU’s can be identified by the product code on the retail box, the Integrated Heat Spreader on the CPU, and by CPU-Z. Use CPU-Z (see Section 8) to read the Revision field below the Stepping field, then record the characters. Use the following link to reference the CPU with Intel's Spec# for Maximum Case Temperature, Stepping, (which determines Maximum Junction Temperature),
Thermal Design Power and Vcore:
http://processorfinder.intel.com/Default.aspx
Intel’s Thermal Specification:
* The thermal specification shown is the maximum case temperature at the maximum Thermal Design Power (TDP) value for that processor. It is measured at the geometric center on the topside of the processor integrated heat spreader.
** For processors without integrated heat spreaders such as mobile processors, the thermal specification is referred to as the junction temperature (Tj). The maximum junction temperature is defined by an activation of the processor Intel® Thermal Monitor. The Intel Thermal Monitor's automatic mode is used to indicate that the maximum TJ has been reached.
Section 3: Interpretation
* The first part of the spec refers to a measuring point on the Integrated Heat Spreader (IHS). Since a thermocouple is embedded in the IHS for lab tests only, IHS temperature is replicated using a CPU Case Thermal Diode integrated between the Cores. Maximum Case Temperature is determined by Spec#. The CPU Case Thermal Diode is how Tcase is measured, and is the CPU temperature displayed in BIOS and in the software utility SpeedFan.
** The second part of the spec refers to mobile processors without Integrated Heat Spreaders (IHS). Although desktop CPU’s have an IHS, both variants measure the hot spots within each Core using Digital Thermal Sensors (DTS). Maximum Junction Temperature is determined by Stepping. The Digital Thermal Sensors are how Tjunction is measured, and are the Core temperatures displayed in the software utilities Core Temp and SpeedFan.
Section 4: Thermal Flow
Heat originates within the Cores, where Tjunction sensors are located within the hot spots of each Core. From the bottom of the Cores, heat dissipates throughout the CPU Case, which creates a thermal gradient toward the center of the Die, where the Tcase sensor is located. Heat then dissipates through the socket and motherboard to air inside the computer case. From the top of the Cores, heat dissipates through the Integrated Heat Spreader and CPU cooler to air inside the computer case. Safe and sustainable temperatures are determined by CPU cooling efficiency, computer case cooling efficiency, Ambient temperature, Vcore, clock speed, Stepping and Load. Tjunction is always higher than Tcase, and Tcase is always higher than Ambient.
Section 5: Findings
(A) Depending upon Stepping, the Delta between Tcase and Tjunction is 10c +/- 3 (or) 15c +/- 3.
(B) Tcase is acquired on the CPU Die from the CPU Case Thermal Diode as an analog level, which is converted to a digital value by the super I/O chip on the motherboard. The digital value is Calibrated in BIOS and displayed by temperature software.
(C) Tjunction is acquired within the Cores from Thermal Diodes as analog levels which are converted to digital values by the Digital Thermal Sensors (DTS) within each Core. The digital values are factory Calibrated and displayed by temperature software.
(D) Tcase and Tjunction are both acquired from Thermal Diodes, however, analog to digital (A to D) conversions are executed by different devices in separate locations. BIOS Calibrations, factory DTS Calibrations and temperature software can all be erroneous.
(E) Core Temp, CPU-Z, Crystal CPUID and SpeedFan will be used for Calibrating Tcase and Tjunction at Idle. Prime95 will then be used for Load testing and SpeedFan will be used for temperature monitoring.
Additional Specifications:
Ambient Temperature = 22c
Idle to Load Delta Max = 25c
Thermal Diode Accuracy = +/-1c
Tjunction Max = 100c (B3, G0, L2, M0 Stepping)
Tjunction Max = 85c (B2 Stepping)
Section 6: Scale
Safe and sustainable temperatures vary according to Spec# and Stepping. The temperature Scales shown below illustrate the maximum 25c Delta between Idle and Load, and the typical 10c +/- 3 (or) 15c +/- 3 Delta between Tcase and Tjunction among C2Q / C2D variants. Although the Delta between Tcase and Tjunction is constant, these temperatures do not always scale in a precisely linear manner with respect to one another due to Variables such as Vcore, clock speed, Stepping and Load. Idle at very low Vcore and clock on G0 Stepping may cause Tcase to Tjunction Delta hottest Core to indicate less than 7c, while 100% Workload at very high Vcore and overclock on B2 Stepping may cause Tcase to Tjunction Delta hottest Core to exceed 18c.
If temperatures increase beyond Hot Scale, then ~ 5c below Tjunction Max, Throttling is activated. The Digital Thermal Sensors (DTS) are used to trigger Intel’s TM1 and TM2 technologies for frequency, multiplier and Vcore Throttling within individual Cores. If Core temperatures increase further to Tjunction Max, then Shutdown occurs. Since Tcase indicates CPU Die temperature only, it is not used for Throttle or Shutdown activation, however, referring to the CPU`s shown below under Scale 1 as examples, Tjunction Throttle temperature is ~ 95c, so Tcase would be ~ 85c which would far exceed Tcase Max. As Tcase to Tjunction Deltas are constant, Tcase Max is always the limiting specification for temperatures.
Since Intel does not correlate information concerning Tcase and Tjunction into a convenient format, use CPU-Z (see Section 8) to read processor information including the Revision field below the Stepping field, then choose a Scale below which applies to the CPU being tested. Scales are ordered from highest to lowest Tcase Max.
Scale 1: Duo
E4x00: Tcase Max 73c, M0 Stepping, Tjunction Max 100c, Vcore Default 1.325, TDP 65w, Delta 10c
E2xx0: Tcase Max 73c, M0 Stepping, Tjunction Max 100c, Vcore Default 1.312, TDP 65w, Delta 10c
E6x50: Tcase Max 72c, G0 Stepping, Tjunction Max 100c, Vcore Default 1.350, TDP 65w, Delta 10c
E6540: Tcase Max 72c, G0 Stepping, Tjunction Max 100c, Vcore Default 1.350, TDP 65w, Delta 10c
-Tcase/Tjunction-
--70--/--80--80-- Hot
--65--/--75--75-- Warm
--60--/--70--70-- Safe
--25--/--35--35-- Cool
Scale 2: Quad
Q6x00: Tcase Max 71c, G0 Stepping, Tjunction Max 100c, Vcore Default 1.372, TDP 95w, Delta 10c
-Tcase/Tjunction-
--70--/--80--80--80--80-- Hot
--65--/--75--75--75--75-- Warm
--60--/--70--70--70--70-- Safe
--25--/--35--35--35--35-- Cool
Scale 3: Quad
QX6x50: Tcase Max 65c, G0 Stepping, Tjunction Max 100c, Vcore Default 1.372, TDP 130w, Delta 10c
QX6800: Tcase Max 65c, G0 Stepping, Tjunction Max 100c, Vcore Default 1.372, TDP 130w, Delta 10c
QX6700: Tcase Max 65c, B3 Stepping, Tjunction Max 100c, Vcore Default 1.372, TDP 130w, Delta 10c
-Tcase/Tjunction-
--65--/--75--75--75--75-- Hot
--60--/--70--70--70--70-- Warm
--55--/--65--65--65--65-- Safe
--25--/--35--35--35--35-- Cool
Scale 4: Quad
Q6600: Tcase Max 62c, B3 Stepping, Tjunction Max 100c, Vcore Default 1.372, TDP 105w, Delta 10c
-Tcase/Tjunction-
--60--/--70--70--70--70-- Hot
--55--/--65--65--65--65-- Warm
--50--/--60--60--60--60-- Safe
--25--/--40--40--40--40-- Cool
Scale 5: Duo
E6x00: Tcase Max 61c, L2 Stepping, Tjunction Max 100c, Vcore Default 1.325, TDP 65w, Delta 15c
E4x00: Tcase Max 61c, L2 Stepping, Tjunction Max 100c, Vcore Default 1.325, TDP 65w, Delta 15c
E21x0: Tcase Max 61c, L2 Stepping, Tjunction Max 100c, Vcore Default 1.312, TDP 65w, Delta 15c
X6800: TcaseMax 60c, B2 Stepping, Tjunction Max 85c, Vcore Default 1.3525, TDP 75w, Delta 15c
E6x00: Tcase Max 60c, B2 Stepping, Tjunction Max 85c, Vcore Default 1.3525, TDP 65w, Delta 15c
E6x20: Tcase Max 60c, B2 Stepping, Tjunction Max 85c, Vcore Default 1.3525, TDP 65w, Delta 15c
-Tcase/Tjunction-
--60--/--75--75-- Hot
--55--/--70--70-- Warm
--50--/--65--65-- Safe
--25--/--40--40-- Cool
Scale 6: Quad
QX6800: Tcase Max 55c, B3 Stepping, Tjunction Max 100c, Vcore Default 1.372, TDP 130w, Delta 10c
-Tcase/Tjunction-
--55--/--65--65--65--65-- Hot
--50--/--60--60--60--60-- Warm
--45--/--55--55--55--55-- Safe
--25--/--40--40--40--40-- Cool
Section 7: Parameters
(A) Vcore should not exceed 1.5 volts.
(B) NO temperatures can be less than Ambient.
(C) Normal Ambient temperature is specified at 22c.
(D) All temperatures increase as Ambient, clock and Vcore increase.
(E) Tcase Idle is always higher than Ambient, even if less than 0.5c.
(F) Tjunction Idle hottest Core is typically no less than 10c +/- 3 higher than
Ambient.
(G) Tcase to Tjunction Delta is ~ 10c on B3 / G0 / M0 Stepping and ~ 15c on B2 / L2 Stepping.
(H) Tjunction Load hottest Core should not exceed Hot Scale for the CPU being tested.
(I) Tcase Load should not exceed Hot Scale for the CPU being tested.
(J) Tjunction Idle and Load Results are always hottest Core.
(K) Idle to Load Delta may exceed 25c when overclocked.
Section 8: Tools
Core Temp, CPU-Z, Crystal CPUID and SpeedFan will be used for Calibrating Tcase and Tjunction at Idle. Prime95 will then be used for Load testing and SpeedFan will provide temperature monitoring. Use the following links to download and install these utilities:
Core Temp 0.96: http://www.alcpu.com/CoreTemp
CPU-Z 1.42: http://www.cpuid.com/cpuz.php
Crystal CPUID 4.13.1.340: http://crystalmark.info/download/i [...] ystalCPUID
Prime95 25.5: http://www.majorgeeks.com/Prime95_d4363.html
SpeedFan 4.33 displays Tcase and Tjunction sensors: http://www.almico.com/speedfan.php
Note 1: It is recommended that Core Temp be used during Calibrations to cross-reference CPU-Z Stepping Revision and SpeedFan Core temperatures.
Note 2: When using Prime95 for the first time, it is necessary to click on Advanced, then click on Round off checking so that errors caused by instabilities will be flagged as they occur. Prime95 will expose insufficient CPU cooling and computer case cooling, or excessive Vcore and overclock. At no other time will a CPU be as heavily loaded, or display higher temperatures, even when OC'd during worst-case loads such as gaming or video editing. Prime95 can be used with SpeedFan to observe CPU temps, while stress testing for system stability. During single threaded gaming and applications, Core 0 typically carries heavier loads and higher temps than other Cores.
Note 3: SpeedFan is very flexible and is the temperature monitoring utility of choice. SpeedFan detects and labels thermal sensors according to various motherboard, chipset and super I/O chip configurations, so the Tcase label can be CPU, Temp 1, Temp 2, or Temp 3. Even if Tcase is labeled as CPU, it is still necessary to confirm the identity of Tcase prior to conducting Calibrations. Run Prime95 and note which SpeedFan temperature scales with an Idle to Load Delta similar to the Cores. This will identify the label corresponding to Tcase. Labels can later be renamed using the Configure button, (see Section 11). If a temperature shows a flame icon, this indicates alarm limits which require adjustment. Use the Configure button to set CPU and Core temp alarms to Safe Scale. If a temperature shows Aux 127, this is simply an unassigned input which can be disabled using the Configure button. CPU’s with Steppings which are Tjunction Max 100c typically require +15c Core Offsets. See Section 11.
Note 4: The software utility TAT, (Thermal Analysis Tool) at maximum settings will simulate 100% Thermal Load, which would equal Prime95 at 114% Workload ~5c hotter. This provides the most extreme testing available for CPU and system cooling efficiency. Since TAT is coded to measure Notebook temps, it identifies a C2D as Pentium M. As Notebooks have no Integrated Heat Spreader, thermal scaling differs from desktop CPU’s, so TAT indicates ~ 2c lower, and depending upon Variables, temps may be Offset by more than 15c. It is therefore recommended that TAT be used for extreme thermal testing only, and temps regarded as unreliable.
Section 9: Calibrations
The purpose of the following procedure is to decrease Idle power consumption and heat dissipation by manually setting BIOS to the lowest common denominators for Vcore and frequency among C2Q / C2D variants and motherboards. The Idle Test is conducted offline with Windows programs closed, 1.25 Vcore, 1.6 Ghz, computer case covers removed, and all fans at 100%. Setting these Variables eliminates cooling issues, and allows all CPU coolers (including Intel’s stock cooler) to decrease Tcase to within 1c above Ambient, which provides for accurate Tcase Offset correction. Tjunction is then validated by reading the Digital Thermal Sensor (DTS) registers, which provides for accurate Tjunction Offset corrections, and also establishes an accurate Tcase to Tjunction Delta.
Note 1: Due to low Vcore and clock settings during the Idle Test, Tcase to Tjunction Delta, hottest Core, may decrease to 7c on B3, G0 and M0 Stepping, and 12c on B2 and L2 Stepping.
Note 2: It is preferred that Idle and Load Tests be conducted as close to 22c Ambient as possible to allow for a normal temperature ceiling for Load Testing, and to maintain environmental consistency for more uniform comparisons among C2Q / C2D variants and system platforms.
Note 3: When configuring Offset corrections, it is desirable to favor positive values, which will provide a safety margin by Calibrating displayed temperatures higher than measured temperatures.
Part 1: Test Setup - Idle
Computer Case Covers = Removed
Computer Case Fans = Manual 100%
Computer Frequency = 1.6 Ghz
Connectivity Status = Offline
CPU Fan = Manual 100%
CPU Internal Thermal Control = Enabled
Enhanced C1 Control (C1E) = Disabled
PECI (If Equipped) = Enabled
Windows Programs = Closed
Speed Step (EIST) = Disabled
Vcore = Manual 1.25
(145 FSB X 11 Multiplier = 1.6 Ghz)
(160 FSB X 10 Multiplier = 1.6 Ghz)
(178 FSB X 9 Multiplier = 1.6 Ghz)
(200 FSB X 8 Multiplier = 1.6 Ghz)
(228 FSB X 7 Multiplier = 1.6 Ghz)
(266 FSB X 6 Multiplier = 1.6 Ghz)
Note 1: PECI (Platform Environmental Control Interface) is a BIOS feature on some recent motherboards which determines the method by which chipsets interpret and manage temperatures. When enabled, thermal accuracy is enhanced, and if disabled, temperatures are typically inverted, where Tcase is higher than Tjunction.
Note 2: Windows programs, background processes, SETI, Folding and Tray software must be closed. Press Ctrl-Alt-Delete, click on Task Manager, then click on the Performance tab to confirm that CPU Usage is less than 2%. Use the Applications and Processes tabs to close programs if necessary. Allow 10 minute at Idle to ensure that temperatures settle to minimums prior to recording Tcase.
Part 2: Tcase Offset Correction
(A) Measure Ambient, preferably near computer case air intake, clear of warm exhaust.
(B) Boot Windows, close programs, allow 10 minutes Idle.
(C) Tcase should indicate Ambient + 1c.
(D) If Offset correction is required, Configure SpeedFan as shown in the Offsets Section.
Note: Under these test conditions, the Tcase thermal gradient may decrease to relatively insignificant values of less than 0.5c above Ambient, however, NO temperatures can be less than Ambient.
Part 3: Tjunction DTS Validation
(A) Open SpeedFan, note hottest Core. Open Crystal CPUID, select same Core in CPU x/x.
(B) In Crystal CPUID, click on Function, then click on MSR Editor.
(C) In the highlighted MSR Number field type 0x19c, then click on the RDMSR button.
(D) In the field under EAX (31-0) record the 5th and 6th characters only, then close Crystal CPUID. (Example = 41)
(E) Open Windows Calculator, click on View, then click on Scientific. Click on Hex then click on Qword.
(F) Type the two characters from Crystal CPUID, then click on Dec and record the Result. (Example = 65)
(G) Open CPU-Z, read the Revision field under the Stepping field, then record the characters. (Example = G0)
(H) Stepping defines Tjunction Max, which is the Intel Specification for Shutdown temp, and is used to determine Tjunction by subtracting the Windows Calculator Result from the appropriate Tjunction Max value, as shown below:
B2 Stepping: Tjunction Max 85c - Result = Tjunction.
B3, G0, L2, M0 Stepping: TJunction Max 100c - Result = Tjunction.
Example: G0 Stepping 100c - Result 65 = Tjunction 35c
Part 4: Tjunction Offset Correction
(A) Tjunction hottest Core should indicate Ambient + 10c +/- 3.
(B) If Offset correction is required, Configure SpeedFan as shown in the Offsets section. Enter identical correction values for each Core. Hottest Core should conform to minimum Parameters.
Note: CPU’s with Steppings which are Tjunction Max 100c typically require +15c Core Offsets. See Section 11.
Part 5: Test Setup - Load
Computer Case Covers = Installed
Computer Case Fans = Manual 100%
Computer Frequency = As Desired
CPU Fan = Manual 100%
CPU Internal Thermal Control = Enabled
Enhanced C1 Control (C1E) = Disabled
PECI (If Equipped) = Enabled
Speed Step (EIST) = Disabled
Vcore = Manual - As Required
Load Test = Prime95 - Small FFT's - 10 Minutes
The Load Test should verify that a Tcase to Tjunction Delta of 10c +/- 3 hottest Core (or) 15c +/- 3 hottest Core is indicated when stock or custom settings are restored following the Idle Test and Offset corrections. If temperatures do not meet the Parameters, then repeat Parts 1 through 5. Remember that Tcase does not always scale in a precisely linear manner with Tjunction due to Variables such as Vcore, clock speed, Stepping and Load. A heavily overclocked system at 1.45 Vcore with B2 Stepping and 100% Workload may exceed 18c Tcase to Tjunction Delta.
If temperatures are allowed to increase beyond Hot Scale, then ~ 5c below Tjunction Max Throttling is activated. The Digital Thermal Sensors (DTS) are used to trigger Intel’s TM1 and TM2 technologies for frequency, multiplier and Vcore Throttling within individual Cores. At this point, Tcase Max has been exceeded. Since Tcase measures CPU Die temperature only, it is not used for Throttle or Shutdown activation. If Core temperatures increase further to Tjunction Max, then Shutdown occurs.
Although recent G0 Stepping CPU's are designed with greater thermal tolerances to better cope with Variables such as temperature fluctuations in high Ambient environments, it is not recommended to continually operate processors, overclocked or stock, at Hot Scale for reasons of stability and longevity.
Section 10: Results and Variables
Example 1: Quad
Tcase = 25c Idle, 50c Load (SpeedFan: CPU or Temp x)
Tjunction = 35c Idle, 60c Load (SpeedFan: Core x) hottest Core
Ambient = 22c
Chipset = P35
CPU = Q6600
CPU Cooler = AC Freezer 7 Pro
Frequency = 3.2 Ghz
Load = Prime95 - Small FFT's - 10 Minutes
Motherboard = Asus P5K Deluxe
Stepping = G0
Vcore = 1.325
Example 2: Duo
Tcase = 30c Idle, 50c Load (SpeedFan: CPU or Temp x)
Tjunction = 45c Idle, 65c Load (SpeedFan: Core x) hottest Core
Ambient = 22c
Chipset = P965
CPU = E6600
CPU Cooler = AC Freezer 7 Pro
Frequency = 3.6 Ghz
Load = Prime95 - Small FFT's - 10 Minutes
Motherboard = Asus P5B Deluxe
Stepping = B2
Vcore = 1.450
The typical 20c Delta between Idle and Load will vary among systems due to inconsistencies such as Ambient temp, Vcore, clock speed, CPU cooling, computer case cooling, graphics card(s) cooling, and software processes. Excessive background processes running simultaneously may not allow low Idle temps. Low Vcore and stock clock may result in low Idle to Load Delta, while high Vcore and overclock may exceed the max spec of 25c Idle to Load Delta.
The typical 10c +/- 3 (or) 15c +/- 3 Delta between Tcase and Tjunction will vary among systems between Idle at low Vcore with G0 Stepping, and Load at high Vcore with B2 Stepping. Erroneous chipsets, super I/O chips, BIOS releases, driver versions, and motherboard utilities often compound temperature inaccuracies. Intel's Thermal Diode spec is +/-1c, so temperatures may be very accurate on hardware / firmware / software platforms free of manufacturer's deficiencies. Temperatures which have Offsets can be accurately Calibrated in SpeedFan.
Section 11: Offsets
If temperatures don't meet Parameters, then SpeedFan 4.33 can configure Offsets to correct for Tcase (CPU or Temp x) and Tjunction (Core x). From the Readings tab, click on the Configure button, then click on the Advanced tab. Next, click on the Chip field directly under the tabs, then use SpeedFan's Help and HOW-TO icon included in the installation Program Group.
Under Contents click on How to configure then click on How to set Advanced Options. Read this section including Other interesting options and Temperature x offset. When configured, SpeedFan will display Tcase and Tjunction temperatures accurately. SpeedFan is also extremely useful for observing temperatures and Vcore using the Charts tab.
Tips:
(A) Tcase = CPU or Temp 1, Temp 2, Temp 3.
(B) Tjunction = Core x.
(C) Core 0 typically carries heavier loads and higher temps during single threaded gaming and applications, so SpeedFan should be configured to "Show in Tray" Core 0.
Section 12: Overclocking
Intel's Thermal Design Power (TDP) spec can be exceeded by over 50% when CPU frequency is aggresively overclocked, and Vcore is increased to maintain stability. Intel's Vcore Default spec of ~ 1.35, when increased much beyond 10% or 1.5 Vcore, makes it challenging to maintain Safe Scale with air cooling. As Ambient temperature increases, overclock frequency and Vcore may need to be decreased.
Every CPU is unique in it's overclock potential, voltage tolerance, and thermal behavior. If the maximum stable overclock is known at 1.35 Vcore, then each increase of 0.05 volts will typically allow a stable increase of ~ 100 Mhz, and will result in a corresponding increase in CPU temperatures of 3 to 4c. Ambient and Vcore are the most dominant Variables affecting temperatures.
At 1.35 Vcore, ~ 300 Mhz of additional overclock remains until Safe Scale is exeeded due to increased Vcore. Example; at 22c Ambient, if a CPU is stable at 3.0 Ghz - 1.35 Vcore @ 100% Workload, then it may also be stable at 3.3 Ghz - 1.5 Vcore @ 100% Workload, with highly effective CPU cooling and computer case cooling.
For more Overclocking information, please refer to the following link: HOWTO:
Overclock C2Q (Quads) and C2D (Duals) - A Guide v1.4 http://www.ocforums.com/showthread.php?t=515316
Section 13: Heat Score
The following items will enable users to estimate cooling efficiency, identify problem areas, and visualize how environment and system configuration impacts real-world thermal performance. Graphics cards which Recirculate heat are a major cause of high temps in gaming rigs, therefore, cards designed with Rear Exhaust are preferred.
(A) Ambient:
3 = Over 24c
2 = 22c to 24c
1 = Under 22c
(B) CPU Cooler:
3 = Stock or Low End
2 = Mid Range
1 = High End
(C) Computer Case Cooling:
3 = Needs Improvement
2 = Fair
1 = Excellent
(D) Frequency:
3 = Heavy OC
2 = Moderate OC
1 = Stock or Lite OC
(E) Graphics Cooling:
3 = Recirculate - SLI
2 = Recirculate - Single Card
1 = Rear Exhaust - Single Card / SLI / CrossFire
(F) Hard Drives:
3 = 4 or More
2 = 2 or 3
1 = 1
(G) Vcore:
3 = Over 1.425
2 = 1.35 to 1.425
1 = Under 1.35
Total: (Example System)
(A) = 2
(B) = 2
(C) = 1
(D) = 3
(E) = 1
(F) = 2
(G) = 3
Heat Score = 14
Scale:
17 - 21 = Hot
12 - 16 = Warm
7 - 11 = Safe
Section 14: Recommendations
(A) For information on CPU Coolers, please refer to the following links:
http://www.anandtech.com/casecooli [...] i=3005&p=4
http://www.bit-tech.net/hardware/200..._tx2_and_212/6
http://www.frostytech.com/articlevie...id=2045&page=4
http://www.madshrimps.be/?action=get...91&articID=519
(B) Masscool Shin-Etsu X23 can reduce CPU temps by ~ 4c compared to Arctic Silver 5, which is far more popular than it is effective. The first link shown below is to a very in-depth Thermal Interface Material (TIM) comparison that was posted 2/2/07 on Tom's Overclocking - Cooler and Heatsinks Forum, which was conducted by DaSickNinja. This 6 page thread is very revealing, however, the review has been moved to the second link shown below, Xtreme CPU.
DaClan Review: Thermal Interface Shootout: http://www.tomshardware.com/forum/22...otout#t1653411
Thermal Interface Material Comparison: http://www.xcpus.com/forums/case-psu...omparison.html
X23 is simply the best Thermal Interface Material (TIM) for CPU cooling, and is available at the following sites:
http://www.chillblast.com/product.php?productid=16932
http://www.ajigo-store.com/se7783d.html
http://www.crazypc.com/products/50118.html
http://www.watercoolingshop.com/ca [...] s_id=496&osCsid=78
Section 15: Troubleshooting
(A) Vcore will typically droop ~ 0.025 volts under Load.
(B) SpeedFan 4.33 may detect Tcase as CPU, Temp 1, Temp 2 or Temp 3.
(C) Offsets between Cores of up to 5c for Quad’s and 3c for Duo’s are normal.
(D) Any hardware and / or software may misreport Tcase and / or Tjunction temps.
(E) 965 chipsets may misreport Tcase and Tjunction temperatures with +/- 15c Offsets.
(F) 6X0 chipsets may misreport Tcase and / or Tjunction accuracy with non-linear scaling.
(G) SpeedFan flame icons are alarm limits which can be adjusted using the Configure button.
(H) SpeedFan Aux 127 is an unassigned input which can be disabled using the Configure button.
(I) SpeedFan 4.33 typically requires +15c Core Offsets for CPU’s with Tjunction Max 100c Steppings.
(J) If Tcase is higher than Tjunction, then enabling PECI (if equipped) in BIOS may correct inverted temps.
(K) CPU's with concave / convex Integrated Heat Spreaders may indicate high Idle to Load Delta.
(L) An improperly seated CPU cooler is the leading cause of abnormally high temperatures.
(M) Ambient and Vcore are the most dominant Variables affecting temperatures.
Author: Computronix
Section 1: Introduction
The purpose of this Guide is to provide users with an understanding of thermal relationships, so that C2Q and C2D temperatures can be uniformly tested, accurately calibrated, and properly monitored. This Guide requires basic familiarity with computer terminology and BIOS menus, but does not require knowledge of unnecessarily diverse or complex technical details. Certain strict definitions have therefore been relaxed to simplify concepts and enhance comprehension.
Intel provides separate thermal specifications for 2 different sensor types; a single Case Thermal Diode located within the CPU die between the Cores, and Digital Thermal Sensors located within each Core. The Case Thermal Diode measures Tcase (Temperature Case), which is commonly known as CPU temp, and the Digital Thermal Sensors measure Tjunction (Temperature Junction), which is commonly known as Core temp. Since these sensors measure 2 distinct thermal levels, there is a constant temperature difference between them, which is referred to as Tcase to Tjunction Delta. C2Q’s have 1 Tcase and 4 Tjunction sensors, while C2D’s have 1 Tcase and 2 Tjunction sensors.
Intel does not provide information which correlates Tcase and Tjunction specifications to normal temperatures and Deltas. Consequently, there is much confusion among users regarding temperature monitoring, software utilities, test methods, Calibrations and Offsets, so Results can be difficult to decipher and compare. When listing Idle & Load test Results, it is also necessary to list the Variables as shown below:
Results and Variables
Tcase = Idle & Load
Tjunction = Idle & Load, hottest Core
Ambient = Room Temp
Chipset = Model
C2Q / C2D = Model
CPU Cooler = Model
Frequency = CPU Clock
Load = Test Program
Motherboard = Model
Stepping = Revision
Vcore = CPU Voltage
Section 2: Specifications
CPU’s can be identified by the product code on the retail box, the Integrated Heat Spreader on the CPU, and by CPU-Z. Use CPU-Z (see Section 8) to read the Revision field below the Stepping field, then record the characters. Use the following link to reference the CPU with Intel's Spec# for Maximum Case Temperature, Stepping, (which determines Maximum Junction Temperature),
Thermal Design Power and Vcore:
http://processorfinder.intel.com/Default.aspx
Intel’s Thermal Specification:
* The thermal specification shown is the maximum case temperature at the maximum Thermal Design Power (TDP) value for that processor. It is measured at the geometric center on the topside of the processor integrated heat spreader.
** For processors without integrated heat spreaders such as mobile processors, the thermal specification is referred to as the junction temperature (Tj). The maximum junction temperature is defined by an activation of the processor Intel® Thermal Monitor. The Intel Thermal Monitor's automatic mode is used to indicate that the maximum TJ has been reached.
Section 3: Interpretation
* The first part of the spec refers to a measuring point on the Integrated Heat Spreader (IHS). Since a thermocouple is embedded in the IHS for lab tests only, IHS temperature is replicated using a CPU Case Thermal Diode integrated between the Cores. Maximum Case Temperature is determined by Spec#. The CPU Case Thermal Diode is how Tcase is measured, and is the CPU temperature displayed in BIOS and in the software utility SpeedFan.
** The second part of the spec refers to mobile processors without Integrated Heat Spreaders (IHS). Although desktop CPU’s have an IHS, both variants measure the hot spots within each Core using Digital Thermal Sensors (DTS). Maximum Junction Temperature is determined by Stepping. The Digital Thermal Sensors are how Tjunction is measured, and are the Core temperatures displayed in the software utilities Core Temp and SpeedFan.
Section 4: Thermal Flow
Heat originates within the Cores, where Tjunction sensors are located within the hot spots of each Core. From the bottom of the Cores, heat dissipates throughout the CPU Case, which creates a thermal gradient toward the center of the Die, where the Tcase sensor is located. Heat then dissipates through the socket and motherboard to air inside the computer case. From the top of the Cores, heat dissipates through the Integrated Heat Spreader and CPU cooler to air inside the computer case. Safe and sustainable temperatures are determined by CPU cooling efficiency, computer case cooling efficiency, Ambient temperature, Vcore, clock speed, Stepping and Load. Tjunction is always higher than Tcase, and Tcase is always higher than Ambient.
Section 5: Findings
(A) Depending upon Stepping, the Delta between Tcase and Tjunction is 10c +/- 3 (or) 15c +/- 3.
(B) Tcase is acquired on the CPU Die from the CPU Case Thermal Diode as an analog level, which is converted to a digital value by the super I/O chip on the motherboard. The digital value is Calibrated in BIOS and displayed by temperature software.
(C) Tjunction is acquired within the Cores from Thermal Diodes as analog levels which are converted to digital values by the Digital Thermal Sensors (DTS) within each Core. The digital values are factory Calibrated and displayed by temperature software.
(D) Tcase and Tjunction are both acquired from Thermal Diodes, however, analog to digital (A to D) conversions are executed by different devices in separate locations. BIOS Calibrations, factory DTS Calibrations and temperature software can all be erroneous.
(E) Core Temp, CPU-Z, Crystal CPUID and SpeedFan will be used for Calibrating Tcase and Tjunction at Idle. Prime95 will then be used for Load testing and SpeedFan will be used for temperature monitoring.
Additional Specifications:
Ambient Temperature = 22c
Idle to Load Delta Max = 25c
Thermal Diode Accuracy = +/-1c
Tjunction Max = 100c (B3, G0, L2, M0 Stepping)
Tjunction Max = 85c (B2 Stepping)
Section 6: Scale
Safe and sustainable temperatures vary according to Spec# and Stepping. The temperature Scales shown below illustrate the maximum 25c Delta between Idle and Load, and the typical 10c +/- 3 (or) 15c +/- 3 Delta between Tcase and Tjunction among C2Q / C2D variants. Although the Delta between Tcase and Tjunction is constant, these temperatures do not always scale in a precisely linear manner with respect to one another due to Variables such as Vcore, clock speed, Stepping and Load. Idle at very low Vcore and clock on G0 Stepping may cause Tcase to Tjunction Delta hottest Core to indicate less than 7c, while 100% Workload at very high Vcore and overclock on B2 Stepping may cause Tcase to Tjunction Delta hottest Core to exceed 18c.
If temperatures increase beyond Hot Scale, then ~ 5c below Tjunction Max, Throttling is activated. The Digital Thermal Sensors (DTS) are used to trigger Intel’s TM1 and TM2 technologies for frequency, multiplier and Vcore Throttling within individual Cores. If Core temperatures increase further to Tjunction Max, then Shutdown occurs. Since Tcase indicates CPU Die temperature only, it is not used for Throttle or Shutdown activation, however, referring to the CPU`s shown below under Scale 1 as examples, Tjunction Throttle temperature is ~ 95c, so Tcase would be ~ 85c which would far exceed Tcase Max. As Tcase to Tjunction Deltas are constant, Tcase Max is always the limiting specification for temperatures.
Since Intel does not correlate information concerning Tcase and Tjunction into a convenient format, use CPU-Z (see Section 8) to read processor information including the Revision field below the Stepping field, then choose a Scale below which applies to the CPU being tested. Scales are ordered from highest to lowest Tcase Max.
Scale 1: Duo
E4x00: Tcase Max 73c, M0 Stepping, Tjunction Max 100c, Vcore Default 1.325, TDP 65w, Delta 10c
E2xx0: Tcase Max 73c, M0 Stepping, Tjunction Max 100c, Vcore Default 1.312, TDP 65w, Delta 10c
E6x50: Tcase Max 72c, G0 Stepping, Tjunction Max 100c, Vcore Default 1.350, TDP 65w, Delta 10c
E6540: Tcase Max 72c, G0 Stepping, Tjunction Max 100c, Vcore Default 1.350, TDP 65w, Delta 10c
-Tcase/Tjunction-
--70--/--80--80-- Hot
--65--/--75--75-- Warm
--60--/--70--70-- Safe
--25--/--35--35-- Cool
Scale 2: Quad
Q6x00: Tcase Max 71c, G0 Stepping, Tjunction Max 100c, Vcore Default 1.372, TDP 95w, Delta 10c
-Tcase/Tjunction-
--70--/--80--80--80--80-- Hot
--65--/--75--75--75--75-- Warm
--60--/--70--70--70--70-- Safe
--25--/--35--35--35--35-- Cool
Scale 3: Quad
QX6x50: Tcase Max 65c, G0 Stepping, Tjunction Max 100c, Vcore Default 1.372, TDP 130w, Delta 10c
QX6800: Tcase Max 65c, G0 Stepping, Tjunction Max 100c, Vcore Default 1.372, TDP 130w, Delta 10c
QX6700: Tcase Max 65c, B3 Stepping, Tjunction Max 100c, Vcore Default 1.372, TDP 130w, Delta 10c
-Tcase/Tjunction-
--65--/--75--75--75--75-- Hot
--60--/--70--70--70--70-- Warm
--55--/--65--65--65--65-- Safe
--25--/--35--35--35--35-- Cool
Scale 4: Quad
Q6600: Tcase Max 62c, B3 Stepping, Tjunction Max 100c, Vcore Default 1.372, TDP 105w, Delta 10c
-Tcase/Tjunction-
--60--/--70--70--70--70-- Hot
--55--/--65--65--65--65-- Warm
--50--/--60--60--60--60-- Safe
--25--/--40--40--40--40-- Cool
Scale 5: Duo
E6x00: Tcase Max 61c, L2 Stepping, Tjunction Max 100c, Vcore Default 1.325, TDP 65w, Delta 15c
E4x00: Tcase Max 61c, L2 Stepping, Tjunction Max 100c, Vcore Default 1.325, TDP 65w, Delta 15c
E21x0: Tcase Max 61c, L2 Stepping, Tjunction Max 100c, Vcore Default 1.312, TDP 65w, Delta 15c
X6800: TcaseMax 60c, B2 Stepping, Tjunction Max 85c, Vcore Default 1.3525, TDP 75w, Delta 15c
E6x00: Tcase Max 60c, B2 Stepping, Tjunction Max 85c, Vcore Default 1.3525, TDP 65w, Delta 15c
E6x20: Tcase Max 60c, B2 Stepping, Tjunction Max 85c, Vcore Default 1.3525, TDP 65w, Delta 15c
-Tcase/Tjunction-
--60--/--75--75-- Hot
--55--/--70--70-- Warm
--50--/--65--65-- Safe
--25--/--40--40-- Cool
Scale 6: Quad
QX6800: Tcase Max 55c, B3 Stepping, Tjunction Max 100c, Vcore Default 1.372, TDP 130w, Delta 10c
-Tcase/Tjunction-
--55--/--65--65--65--65-- Hot
--50--/--60--60--60--60-- Warm
--45--/--55--55--55--55-- Safe
--25--/--40--40--40--40-- Cool
Section 7: Parameters
(A) Vcore should not exceed 1.5 volts.
(B) NO temperatures can be less than Ambient.
(C) Normal Ambient temperature is specified at 22c.
(D) All temperatures increase as Ambient, clock and Vcore increase.
(E) Tcase Idle is always higher than Ambient, even if less than 0.5c.
(F) Tjunction Idle hottest Core is typically no less than 10c +/- 3 higher than
Ambient.
(G) Tcase to Tjunction Delta is ~ 10c on B3 / G0 / M0 Stepping and ~ 15c on B2 / L2 Stepping.
(H) Tjunction Load hottest Core should not exceed Hot Scale for the CPU being tested.
(I) Tcase Load should not exceed Hot Scale for the CPU being tested.
(J) Tjunction Idle and Load Results are always hottest Core.
(K) Idle to Load Delta may exceed 25c when overclocked.
Section 8: Tools
Core Temp, CPU-Z, Crystal CPUID and SpeedFan will be used for Calibrating Tcase and Tjunction at Idle. Prime95 will then be used for Load testing and SpeedFan will provide temperature monitoring. Use the following links to download and install these utilities:
Core Temp 0.96: http://www.alcpu.com/CoreTemp
CPU-Z 1.42: http://www.cpuid.com/cpuz.php
Crystal CPUID 4.13.1.340: http://crystalmark.info/download/i [...] ystalCPUID
Prime95 25.5: http://www.majorgeeks.com/Prime95_d4363.html
SpeedFan 4.33 displays Tcase and Tjunction sensors: http://www.almico.com/speedfan.php
Note 1: It is recommended that Core Temp be used during Calibrations to cross-reference CPU-Z Stepping Revision and SpeedFan Core temperatures.
Note 2: When using Prime95 for the first time, it is necessary to click on Advanced, then click on Round off checking so that errors caused by instabilities will be flagged as they occur. Prime95 will expose insufficient CPU cooling and computer case cooling, or excessive Vcore and overclock. At no other time will a CPU be as heavily loaded, or display higher temperatures, even when OC'd during worst-case loads such as gaming or video editing. Prime95 can be used with SpeedFan to observe CPU temps, while stress testing for system stability. During single threaded gaming and applications, Core 0 typically carries heavier loads and higher temps than other Cores.
Note 3: SpeedFan is very flexible and is the temperature monitoring utility of choice. SpeedFan detects and labels thermal sensors according to various motherboard, chipset and super I/O chip configurations, so the Tcase label can be CPU, Temp 1, Temp 2, or Temp 3. Even if Tcase is labeled as CPU, it is still necessary to confirm the identity of Tcase prior to conducting Calibrations. Run Prime95 and note which SpeedFan temperature scales with an Idle to Load Delta similar to the Cores. This will identify the label corresponding to Tcase. Labels can later be renamed using the Configure button, (see Section 11). If a temperature shows a flame icon, this indicates alarm limits which require adjustment. Use the Configure button to set CPU and Core temp alarms to Safe Scale. If a temperature shows Aux 127, this is simply an unassigned input which can be disabled using the Configure button. CPU’s with Steppings which are Tjunction Max 100c typically require +15c Core Offsets. See Section 11.
Note 4: The software utility TAT, (Thermal Analysis Tool) at maximum settings will simulate 100% Thermal Load, which would equal Prime95 at 114% Workload ~5c hotter. This provides the most extreme testing available for CPU and system cooling efficiency. Since TAT is coded to measure Notebook temps, it identifies a C2D as Pentium M. As Notebooks have no Integrated Heat Spreader, thermal scaling differs from desktop CPU’s, so TAT indicates ~ 2c lower, and depending upon Variables, temps may be Offset by more than 15c. It is therefore recommended that TAT be used for extreme thermal testing only, and temps regarded as unreliable.
Section 9: Calibrations
The purpose of the following procedure is to decrease Idle power consumption and heat dissipation by manually setting BIOS to the lowest common denominators for Vcore and frequency among C2Q / C2D variants and motherboards. The Idle Test is conducted offline with Windows programs closed, 1.25 Vcore, 1.6 Ghz, computer case covers removed, and all fans at 100%. Setting these Variables eliminates cooling issues, and allows all CPU coolers (including Intel’s stock cooler) to decrease Tcase to within 1c above Ambient, which provides for accurate Tcase Offset correction. Tjunction is then validated by reading the Digital Thermal Sensor (DTS) registers, which provides for accurate Tjunction Offset corrections, and also establishes an accurate Tcase to Tjunction Delta.
Note 1: Due to low Vcore and clock settings during the Idle Test, Tcase to Tjunction Delta, hottest Core, may decrease to 7c on B3, G0 and M0 Stepping, and 12c on B2 and L2 Stepping.
Note 2: It is preferred that Idle and Load Tests be conducted as close to 22c Ambient as possible to allow for a normal temperature ceiling for Load Testing, and to maintain environmental consistency for more uniform comparisons among C2Q / C2D variants and system platforms.
Note 3: When configuring Offset corrections, it is desirable to favor positive values, which will provide a safety margin by Calibrating displayed temperatures higher than measured temperatures.
Part 1: Test Setup - Idle
Computer Case Covers = Removed
Computer Case Fans = Manual 100%
Computer Frequency = 1.6 Ghz
Connectivity Status = Offline
CPU Fan = Manual 100%
CPU Internal Thermal Control = Enabled
Enhanced C1 Control (C1E) = Disabled
PECI (If Equipped) = Enabled
Windows Programs = Closed
Speed Step (EIST) = Disabled
Vcore = Manual 1.25
(145 FSB X 11 Multiplier = 1.6 Ghz)
(160 FSB X 10 Multiplier = 1.6 Ghz)
(178 FSB X 9 Multiplier = 1.6 Ghz)
(200 FSB X 8 Multiplier = 1.6 Ghz)
(228 FSB X 7 Multiplier = 1.6 Ghz)
(266 FSB X 6 Multiplier = 1.6 Ghz)
Note 1: PECI (Platform Environmental Control Interface) is a BIOS feature on some recent motherboards which determines the method by which chipsets interpret and manage temperatures. When enabled, thermal accuracy is enhanced, and if disabled, temperatures are typically inverted, where Tcase is higher than Tjunction.
Note 2: Windows programs, background processes, SETI, Folding and Tray software must be closed. Press Ctrl-Alt-Delete, click on Task Manager, then click on the Performance tab to confirm that CPU Usage is less than 2%. Use the Applications and Processes tabs to close programs if necessary. Allow 10 minute at Idle to ensure that temperatures settle to minimums prior to recording Tcase.
Part 2: Tcase Offset Correction
(A) Measure Ambient, preferably near computer case air intake, clear of warm exhaust.
(B) Boot Windows, close programs, allow 10 minutes Idle.
(C) Tcase should indicate Ambient + 1c.
(D) If Offset correction is required, Configure SpeedFan as shown in the Offsets Section.
Note: Under these test conditions, the Tcase thermal gradient may decrease to relatively insignificant values of less than 0.5c above Ambient, however, NO temperatures can be less than Ambient.
Part 3: Tjunction DTS Validation
(A) Open SpeedFan, note hottest Core. Open Crystal CPUID, select same Core in CPU x/x.
(B) In Crystal CPUID, click on Function, then click on MSR Editor.
(C) In the highlighted MSR Number field type 0x19c, then click on the RDMSR button.
(D) In the field under EAX (31-0) record the 5th and 6th characters only, then close Crystal CPUID. (Example = 41)
(E) Open Windows Calculator, click on View, then click on Scientific. Click on Hex then click on Qword.
(F) Type the two characters from Crystal CPUID, then click on Dec and record the Result. (Example = 65)
(G) Open CPU-Z, read the Revision field under the Stepping field, then record the characters. (Example = G0)
(H) Stepping defines Tjunction Max, which is the Intel Specification for Shutdown temp, and is used to determine Tjunction by subtracting the Windows Calculator Result from the appropriate Tjunction Max value, as shown below:
B2 Stepping: Tjunction Max 85c - Result = Tjunction.
B3, G0, L2, M0 Stepping: TJunction Max 100c - Result = Tjunction.
Example: G0 Stepping 100c - Result 65 = Tjunction 35c
Part 4: Tjunction Offset Correction
(A) Tjunction hottest Core should indicate Ambient + 10c +/- 3.
(B) If Offset correction is required, Configure SpeedFan as shown in the Offsets section. Enter identical correction values for each Core. Hottest Core should conform to minimum Parameters.
Note: CPU’s with Steppings which are Tjunction Max 100c typically require +15c Core Offsets. See Section 11.
Part 5: Test Setup - Load
Computer Case Covers = Installed
Computer Case Fans = Manual 100%
Computer Frequency = As Desired
CPU Fan = Manual 100%
CPU Internal Thermal Control = Enabled
Enhanced C1 Control (C1E) = Disabled
PECI (If Equipped) = Enabled
Speed Step (EIST) = Disabled
Vcore = Manual - As Required
Load Test = Prime95 - Small FFT's - 10 Minutes
The Load Test should verify that a Tcase to Tjunction Delta of 10c +/- 3 hottest Core (or) 15c +/- 3 hottest Core is indicated when stock or custom settings are restored following the Idle Test and Offset corrections. If temperatures do not meet the Parameters, then repeat Parts 1 through 5. Remember that Tcase does not always scale in a precisely linear manner with Tjunction due to Variables such as Vcore, clock speed, Stepping and Load. A heavily overclocked system at 1.45 Vcore with B2 Stepping and 100% Workload may exceed 18c Tcase to Tjunction Delta.
If temperatures are allowed to increase beyond Hot Scale, then ~ 5c below Tjunction Max Throttling is activated. The Digital Thermal Sensors (DTS) are used to trigger Intel’s TM1 and TM2 technologies for frequency, multiplier and Vcore Throttling within individual Cores. At this point, Tcase Max has been exceeded. Since Tcase measures CPU Die temperature only, it is not used for Throttle or Shutdown activation. If Core temperatures increase further to Tjunction Max, then Shutdown occurs.
Although recent G0 Stepping CPU's are designed with greater thermal tolerances to better cope with Variables such as temperature fluctuations in high Ambient environments, it is not recommended to continually operate processors, overclocked or stock, at Hot Scale for reasons of stability and longevity.
Section 10: Results and Variables
Example 1: Quad
Tcase = 25c Idle, 50c Load (SpeedFan: CPU or Temp x)
Tjunction = 35c Idle, 60c Load (SpeedFan: Core x) hottest Core
Ambient = 22c
Chipset = P35
CPU = Q6600
CPU Cooler = AC Freezer 7 Pro
Frequency = 3.2 Ghz
Load = Prime95 - Small FFT's - 10 Minutes
Motherboard = Asus P5K Deluxe
Stepping = G0
Vcore = 1.325
Example 2: Duo
Tcase = 30c Idle, 50c Load (SpeedFan: CPU or Temp x)
Tjunction = 45c Idle, 65c Load (SpeedFan: Core x) hottest Core
Ambient = 22c
Chipset = P965
CPU = E6600
CPU Cooler = AC Freezer 7 Pro
Frequency = 3.6 Ghz
Load = Prime95 - Small FFT's - 10 Minutes
Motherboard = Asus P5B Deluxe
Stepping = B2
Vcore = 1.450
The typical 20c Delta between Idle and Load will vary among systems due to inconsistencies such as Ambient temp, Vcore, clock speed, CPU cooling, computer case cooling, graphics card(s) cooling, and software processes. Excessive background processes running simultaneously may not allow low Idle temps. Low Vcore and stock clock may result in low Idle to Load Delta, while high Vcore and overclock may exceed the max spec of 25c Idle to Load Delta.
The typical 10c +/- 3 (or) 15c +/- 3 Delta between Tcase and Tjunction will vary among systems between Idle at low Vcore with G0 Stepping, and Load at high Vcore with B2 Stepping. Erroneous chipsets, super I/O chips, BIOS releases, driver versions, and motherboard utilities often compound temperature inaccuracies. Intel's Thermal Diode spec is +/-1c, so temperatures may be very accurate on hardware / firmware / software platforms free of manufacturer's deficiencies. Temperatures which have Offsets can be accurately Calibrated in SpeedFan.
Section 11: Offsets
If temperatures don't meet Parameters, then SpeedFan 4.33 can configure Offsets to correct for Tcase (CPU or Temp x) and Tjunction (Core x). From the Readings tab, click on the Configure button, then click on the Advanced tab. Next, click on the Chip field directly under the tabs, then use SpeedFan's Help and HOW-TO icon included in the installation Program Group.
Under Contents click on How to configure then click on How to set Advanced Options. Read this section including Other interesting options and Temperature x offset. When configured, SpeedFan will display Tcase and Tjunction temperatures accurately. SpeedFan is also extremely useful for observing temperatures and Vcore using the Charts tab.
Tips:
(A) Tcase = CPU or Temp 1, Temp 2, Temp 3.
(B) Tjunction = Core x.
(C) Core 0 typically carries heavier loads and higher temps during single threaded gaming and applications, so SpeedFan should be configured to "Show in Tray" Core 0.
Section 12: Overclocking
Intel's Thermal Design Power (TDP) spec can be exceeded by over 50% when CPU frequency is aggresively overclocked, and Vcore is increased to maintain stability. Intel's Vcore Default spec of ~ 1.35, when increased much beyond 10% or 1.5 Vcore, makes it challenging to maintain Safe Scale with air cooling. As Ambient temperature increases, overclock frequency and Vcore may need to be decreased.
Every CPU is unique in it's overclock potential, voltage tolerance, and thermal behavior. If the maximum stable overclock is known at 1.35 Vcore, then each increase of 0.05 volts will typically allow a stable increase of ~ 100 Mhz, and will result in a corresponding increase in CPU temperatures of 3 to 4c. Ambient and Vcore are the most dominant Variables affecting temperatures.
At 1.35 Vcore, ~ 300 Mhz of additional overclock remains until Safe Scale is exeeded due to increased Vcore. Example; at 22c Ambient, if a CPU is stable at 3.0 Ghz - 1.35 Vcore @ 100% Workload, then it may also be stable at 3.3 Ghz - 1.5 Vcore @ 100% Workload, with highly effective CPU cooling and computer case cooling.
For more Overclocking information, please refer to the following link: HOWTO:
Overclock C2Q (Quads) and C2D (Duals) - A Guide v1.4 http://www.ocforums.com/showthread.php?t=515316
Section 13: Heat Score
The following items will enable users to estimate cooling efficiency, identify problem areas, and visualize how environment and system configuration impacts real-world thermal performance. Graphics cards which Recirculate heat are a major cause of high temps in gaming rigs, therefore, cards designed with Rear Exhaust are preferred.
(A) Ambient:
3 = Over 24c
2 = 22c to 24c
1 = Under 22c
(B) CPU Cooler:
3 = Stock or Low End
2 = Mid Range
1 = High End
(C) Computer Case Cooling:
3 = Needs Improvement
2 = Fair
1 = Excellent
(D) Frequency:
3 = Heavy OC
2 = Moderate OC
1 = Stock or Lite OC
(E) Graphics Cooling:
3 = Recirculate - SLI
2 = Recirculate - Single Card
1 = Rear Exhaust - Single Card / SLI / CrossFire
(F) Hard Drives:
3 = 4 or More
2 = 2 or 3
1 = 1
(G) Vcore:
3 = Over 1.425
2 = 1.35 to 1.425
1 = Under 1.35
Total: (Example System)
(A) = 2
(B) = 2
(C) = 1
(D) = 3
(E) = 1
(F) = 2
(G) = 3
Heat Score = 14
Scale:
17 - 21 = Hot
12 - 16 = Warm
7 - 11 = Safe
Section 14: Recommendations
(A) For information on CPU Coolers, please refer to the following links:
http://www.anandtech.com/casecooli [...] i=3005&p=4
http://www.bit-tech.net/hardware/200..._tx2_and_212/6
http://www.frostytech.com/articlevie...id=2045&page=4
http://www.madshrimps.be/?action=get...91&articID=519
(B) Masscool Shin-Etsu X23 can reduce CPU temps by ~ 4c compared to Arctic Silver 5, which is far more popular than it is effective. The first link shown below is to a very in-depth Thermal Interface Material (TIM) comparison that was posted 2/2/07 on Tom's Overclocking - Cooler and Heatsinks Forum, which was conducted by DaSickNinja. This 6 page thread is very revealing, however, the review has been moved to the second link shown below, Xtreme CPU.
DaClan Review: Thermal Interface Shootout: http://www.tomshardware.com/forum/22...otout#t1653411
Thermal Interface Material Comparison: http://www.xcpus.com/forums/case-psu...omparison.html
X23 is simply the best Thermal Interface Material (TIM) for CPU cooling, and is available at the following sites:
http://www.chillblast.com/product.php?productid=16932
http://www.ajigo-store.com/se7783d.html
http://www.crazypc.com/products/50118.html
http://www.watercoolingshop.com/ca [...] s_id=496&osCsid=78
Section 15: Troubleshooting
(A) Vcore will typically droop ~ 0.025 volts under Load.
(B) SpeedFan 4.33 may detect Tcase as CPU, Temp 1, Temp 2 or Temp 3.
(C) Offsets between Cores of up to 5c for Quad’s and 3c for Duo’s are normal.
(D) Any hardware and / or software may misreport Tcase and / or Tjunction temps.
(E) 965 chipsets may misreport Tcase and Tjunction temperatures with +/- 15c Offsets.
(F) 6X0 chipsets may misreport Tcase and / or Tjunction accuracy with non-linear scaling.
(G) SpeedFan flame icons are alarm limits which can be adjusted using the Configure button.
(H) SpeedFan Aux 127 is an unassigned input which can be disabled using the Configure button.
(I) SpeedFan 4.33 typically requires +15c Core Offsets for CPU’s with Tjunction Max 100c Steppings.
(J) If Tcase is higher than Tjunction, then enabling PECI (if equipped) in BIOS may correct inverted temps.
(K) CPU's with concave / convex Integrated Heat Spreaders may indicate high Idle to Load Delta.
(L) An improperly seated CPU cooler is the leading cause of abnormally high temperatures.
(M) Ambient and Vcore are the most dominant Variables affecting temperatures.
Author: Computronix
