i7 950 CPU Overclocking getting Memtest Errors

Hello,

I'm fairly new to overclocking but have a strong understanding of computers as a whole. I've managed to get my i7950 to go from 3.02 to 3.8, temp around 70C full load. It seems stable but when I run memtest 4.10 from my bootable usb stick it brings up errors approx 5. I've run memtest with the default bios settings and there were 0 errors, so it must have something to do with my overclocking settings.

Below are my computer specs and overclocking settings;

Intel i7 950
MB:Asus P6X58D-E
Ram 24gigs:4GBx3 Mushkin Enhanced Backline Frostbyte PC3-12800 DDR3-1600 9-9-9-24
4GBx3 Corsair Vengeance DDR3-1600 9-9-9-24 XMP

Bios Overclocked Settings
Ai Overclock Tuner - Manual
CPU Ratio Settging - 21.0
Intel Speedstech Tech - Disabled
Xtreme Phase Full Power Mode - Enabled
BCLK Frequency - 181
PCIE Frequency - 100
DRAM Frequency - DDR3-1451MHz
UCLK Frequency - 2903MHz
QPI Link Data Rate - 6532MT/s

CPU Voltage Control - Manual
CPU Voltage - 1.2
CPU PLL Voltage - 1.88
QPI/DRAM Core Voltage - 1.2
IOH Voltage - 1.10
IOH PCIE Voltage - 1.5
ICH Voltage - 1.2
ICH PCIE Voltage - 1.5
DRAM Bus Voltage - 1.5

Load - Line Calibration - Enabled
CPU Differential Amplitude - 800mV
CPU Clock Skew - Auto
CPU Spread Spectrum - Disabled
IOH Clock Skew - Auto
PCIE Spread Specturm - Disabled

DRAM Timing Control
DRAM CAS# Latency - 9 DRAM Clock
DRAM RAS# to CAS# Delay - 9 DRAM Clock
DRAM RAS# PRE Time - 9 DRAM Clock
DRAM RAS# ACT Time - 24 Dram Clock

Advanced
CPU Ratio Setting - 21.0
C1E Support - Disabled
Hardware Prefetcher - Enabled
Adjacent Cache Line Prefetch - Enabled
Intel Virtualization Tech - Disabled
CPU TM Funtion - Disabled
Excute Disable Bit - Enabled
Intel HT Technology - Enabled
Active Processor Cores - All
A20M - Disabled

Intel PPM Configuration
Intel SpeedStep Tech - Disabled
Intel C-State Tech - Disabled

According to your information listed, you're running your RAM at DDR3 1451, that would be underclock from DDR3 1600, not an overclock. Not sure why that would cause any errors in memtest.

If your RAM passes memtest without errors at stock speeds then you should adjust your FSB/CPU multi/RAM multi until you get a desired CPU overclock with RAM at stock. AFTER you get everything stable with RAM at stock THEN you should try overclocking the RAM.

Make sure you're running the latest v4.20 of Memtest86+...

http://www.memtest.org/

Also change the BCLK to 200 w/ the multiplier at x19 = 3.8GHz / DRAM Freq. = DDR3-1600, UCLK Freq. and QPI Link Data Rate to Auto, QPI/DRAM Core voltage to 1.35V (all other voltages on Auto, except DRAM voltage set to 1.52-1.55V, and Vcore set to 1.25V). Manually adjust the four primary DRAM timings to 9-9-9-24-2T, and leave the rest of the sub-timings on Auto.

Okay I've done everything you guys have posted. Except when I changed; QPI/DRAM Core voltage to 1.35V, Vcore set to 1.25V the overclock failed.

Here is the new config I'm memtesting now;

Intel i7 950
MB:Asus P6X58D-E
Ram 24gigs:4GBx3 Mushkin Enhanced Backline Frostbyte PC3-12800 DDR3-1600 9-9-9-24
4GBx3 Corsair Vengeance DDR3-1600 9-9-9-24 XMP

Bios Overclocked Settings
Ai Overclock Tuner - Manual
CPU Ratio Settging - 19.0
Intel Speedstech Tech - Disabled
Xtreme Phase Full Power Mode - Enabled
BCLK Frequency - 200
PCIE Frequency - 100
DRAM Frequency - DDR3-1603MHz
UCLK Frequency -auto
QPI Link Data Rate - auto

CPU Voltage Control - Manual
CPU Voltage - 1.2
CPU PLL Voltage - 1.88
QPI/DRAM Core Voltage - 1.2
IOH Voltage - auto
IOH PCIE Voltage - auto
ICH Voltage - auto
ICH PCIE Voltage - auto
DRAM Bus Voltage - 1.52

Load - Line Calibration - Enabled
CPU Differential Amplitude - 800mV
CPU Clock Skew - Auto
CPU Spread Spectrum - Disabled
IOH Clock Skew - Auto
PCIE Spread Specturm - Disabled

DRAM Timing Control
DRAM CAS# Latency - 9 DRAM Clock
DRAM RAS# to CAS# Delay - 9 DRAM Clock
DRAM RAS# PRE Time - 9 DRAM Clock
DRAM RAS# ACT Time - 24 Dram Clock

Advanced
CPU Ratio Setting - 19
C1E Support - Disabled
Hardware Prefetcher - Enabled
Adjacent Cache Line Prefetch - Enabled
Intel Virtualization Tech - Disabled
CPU TM Funtion - Disabled
Excute Disable Bit - Enabled
Intel HT Technology - Enabled
Active Processor Cores - All
A20M - Disabled

Intel PPM Configuration
Intel SpeedStep Tech - Disabled
Intel C-State Tech - Disabled

Okay the above config passed memtest with no errors. However things are a little hot. Upon boot into windows idles at 49. When I run prime 95 third option I taper off at around 83c.

Is there any good way to keep my overclock at 3.8 but have the CPU run cooler?

Disable HT and Turbo, then lower the Vcore to 1.12-1.15V.

buzert said:

Okay the above config passed memtest with no errors. However things are a little hot. Upon boot into windows idles at 49. When I run prime 95 third option I taper off at around 83c.

Is there any good way to keep my overclock at 3.8 but have the CPU run cooler?

Click to expand...

Did you ever mention what type of cooling you have?

Noctua NH-U12P is my cooling

I'm sure there are cooler solutions but I'm going to stick with what I have and see if I can drop the temps via bios and the help of you guys.

hey redduc can I still lower the vcore even if I dont disable ht and turbo? I'd like to keep them on as this computer will be used for rendering.

You're the only one that can know for sure whether or not you can lower the Vcore. You'll just have to stress the system w/ something like OCCT, LinX. Prime, etc. until one or the other fails, then bump it up to a point where it passes / the system runs stably. At least disable Turbo if you want to keep HT enabled, but personally I would just disable both.

I can't seem to find the turbo anywhere in my bios? Could it be listed as something else? EDIT: I just read that the turbo will not show up if the speedstep tech is disabled.What does turbo do and if I shut it off what am I missing out on? EDIT: Looks like it's something I'm not going to miss out on for rendering so I'll keep it off.Here is a link to all my screens in the bios;
http://www.bjorn3d.com/2010/07/asus-p6x58d-e/

Okay, I've managed to answer my own questions above but posted in for others who have the same goals.
My next goal is to get that temperature down by slowly decreasing the Vcore until it's as low as it can go and stable.

I've very happy with the responses so for and I've almost got the perfect overclocked system. My last step will be to try and overclock the ram. I need your help with this. It seems like there are 3 parts of the ram that can be overclocked (dram voltage, timing and frequency). So which one do I increase first, second and third? When I finally do get to the timing what is the next logical increase of speed to 9-9-9-24?

Okay the turbo is off, left the HT on because it helps with rendering. I've managed to get the vcore stable at 1.18 but just to be safe I've left it at 1.19.

My temps from prime 95 option 3 are 85 85 82 82.

Is that too hot for full load? If so what do I do next? Do I drop it down to 3.6? If so what do I change in the bios?

After many days of testing I'm happy to say that despite prime95 giving me high temps my rendering is not. My rendering temps after days are 5-10C cooler, I'm now in spec.

To sum it up my gains are; i7950 3.02 - 3.8 stable
Cooling: Noctura NH-U12P SE2

Thank you all for your help.