General FX-8120 Coretemp question

[DarthGrantius]

Hi guys,

I have an FX-8120 currently at 3.9ghz (17.5 @ 223HT), a Thermolab Bada cooler and my RAM which was 1333 stock sitting at 1487 or so, sitting pretty close to as stable as I can get it and I am more then happy with it so far

As I understand it Coretemp under-reports temperatures by around 12c, so under a p95 load I get around 44c as reported by Coretemp - meaning close to 56c real life temp.

What kind of temps do you guys get with these chips with Coretemp and is my assumption with the offset of 12c correct?

 

[BeepBeep2]

More like 15-20c, two samples I have tested were both about 20c off, checked with probe.
12c is very particular...don't know who came up with that exact number but not all are exactly the same either.

I've seen the CPUs read 8-9c on water, and I know for a fact that CPUs don't idle 20c in a 20c room...30 reasonable.

 

[RGone]

Honestly we move most everyone over to HWMonitor when we help with the 'tweaking' thing. That puts the user and us on the same page. HWMonitor gives both a cpu core temp and a cpu temp. We are accustomed to reading the two temps and are suggesting 60c on the core temps and 70c on the cpu temps AS shown by HWMonitor.

The problem for us in making suggestions is that each of these software monitors use a diffferent calculation to reach the temp number they display. So you can use whatever you want to to monitor the temps, we just are not really accustomed to CoreTemp.

I have 'heard' the same thing about CoreTemp you heard, but I don't use it an most everyone posting in here uses HWMonitor during the period of time we help with the tweaking process. Luck man and be well.

 

[BeepBeep2]

RGone, CoreTemp reads from the CPU so it is the same as listed in HWMonitor under CPU name and Core #s. They don't calculate much of anything unless they are reading wrong. How to read the sensor raw values is governed by AMD/intel/Windbond/whoever...

Depending on motherboard, HWMonitor will not read out the motherboard sensor...and on Gigabyte boards I know for a fact they read 5-10c low even still.

 

[RGone]

Maybe CoreTemp reads with HWMonitor CPU Core Temps now and that is okay by me. I don't use CoreTemp as I told the OP. CoreTemp stays in RC mode so I don't do anything with it.

 

[BeepBeep2]

Uhh...ok but it has always been that way, it was never different. Franck and Arthur use the same formulas to derive temperature.

What do you mean by RC Mode? It is a program that reads CPU temperature...what else do you expect it to do? It is not designed to read the ITF or Winbond hubs on motherboards, where HWBOT gets it's 3 motherboard temps (sometimes including CPU/NB/SB etc) and voltage readings however CoreTemp allows you to enter an offset temperature in case you physically measure it and want to make the program more accurate for yourself.

Intel defines a certain Tjunction temperature for the processor. This value is usually in the range between 85°C and 105°C. In the later generation of processors, starting with Nehalem, the exact Tjunction Max value is available for software to read in an MSR (short for Model Specific Register).
A different MSR contains the temperature data. The data is represented as a Delta in °C between current temperature and Tjunction.

So the actual temperature is calculated like this 'Core Temp = Tjunction - Delta'

The size of the data field is 7 bits. This means a Delta of 0 - 127°C can be reported in theory. In fact the reported temperature can rarely go below 0°C and in some cases (Core 2 - 45nm series) temperatures below 30° or even 40°C are not reported.

AMD processors report the temperature via a special register in the CPU's northbridge. Core Temp reads the value from the register and uses a formula provided by AMD to calculate the current temperature.
The formula for the Athlon 64 series, early Opterons and Semprons (K8 architecture) is: 'Core Temp = Value - 49'.
For the newer generation of AMD processors like Phenom, Phenom II, newer Athlons, Semprons and Opterons (K10 architecture and up), and their derivatives, there is a different formula: 'CPU Temp* = Value / 8'.

*CPU Temp is because the Phenom\Opteron (K10) have only one sensor per package, meaning there is only one reading per processor.

VIA processors are capable of reporting the temperature of each core. The thermal sensor provides an absolute temperature value in Celsius, there is no need for any conversion or manipulation.

The Tjunction or TjMax temperature on VIA chips is usually between 70 and 90C. 90C for the mobile and low power versions and 70C is for the desktop variants.

 

[DarthGrantius]

Thanks everyone for the replies - its a pity AMD didn't add a proper sensor or wattage calculations like Intel do...

Uhh...ok but it has always been that way, it was never different. Franck and Arthur use the same formulas to derive temperature.

What do you mean by RC Mode? It is a program that reads CPU temperature...what else do you expect it to do? It is not designed to read the ITF or Winbond hubs on motherboards, where HWBOT gets it's 3 motherboard temps (sometimes including CPU/NB/SB etc) and voltage readings however CoreTemp allows you to enter an offset temperature in case you physically measure it and want to make the program more accurate for yourself.

My bios is odd, CPU-Z vcore stays the same no matter what I set in the bios but when I look at my SuperIO ITF read-outs with HWbot it reports my changed Vcore there?

 

[trents]

. . . Depending on motherboard, HWMonitor will not read out the motherboard sensor...and on Gigabyte boards I know for a fact they read 5-10c low even still.

I think HWMonitor is sometimes not able to identify which motherboard sensor is the CPU (socket) temp sensor so it gives it one of those "TMPINx" generic designations and the user is left to guess which one it is. I could be wrong but that's the impression I get from using it for a long time.

 

[BeepBeep2]

I think HWMonitor is sometimes not able to identify which motherboard sensor is the CPU (socket) temp sensor so it gives it one of those "TMPINx" generic designations and the user is left to guess which one it is. I could be wrong but that's the impression I get from using it for a long time.

Yes. I believe that when the manufacturer leaves the register unlabeled (the part of the Winbond, ITF, etc chip that reports the values to software, it just reads TMPIN1, TMPIN2, TMPIN3, which are the default in the chip.

Same goes with "FANIN0, FANIN1" etc.

 

[GamerMagnet]

today I did a little test to see how accurate my core temps shown on HWmonitor. With a Fluke 561 infrared temp gun and a probe I measured the surface temp of the cpu. With 4.3ghz @ 1.34v HWmonitor read 56c on my cores. With the gun the temps read 59c. I own a gigabye 990fxa-ud5 and that temp seems pretty close. Not close to 12c, but then again not all are alike.

 

[RGone]

today I did a little test to see how accurate my core temps shown on HWmonitor. With a Fluke 561 infrared temp gun and a probe I measured the surface temp of the cpu. With 4.3ghz @ 1.34v HWmonitor read 56c on my cores. With the gun the temps read 59c. I own a gigabye 990fxa-ud5 and that temp seems pretty close. Not close to 12c, but then again not all are alike.

You know G_M, that is not too surprising overall. AMD nor Intel really care about an Idle temperature. They are only concerned with a too high temperature. Too high a temperature to monitor for raising the core multpliier for added power and too high a temperature for the life of the processor.

 

[BeepBeep2]

Please explain to me how you read the temperature with an infrared temp gun on the CPU IHS...when it was running under Prime
Reading even the side of the IHS is not close to accurate, most heat is concentrated in the middle half of surface area spreading into the socket.

If you really want to find real temperature, then a slit needs to be cut in the CPU IHS to insert a thermocouple.

 

[DarthGrantius]

I have it set to 15c higher just to be on the safe side

thanks for the feedback!

 

[caddi daddi]

have any of you tried hardware monitor version 1.2?
it is quite different from 1.18.