I7 920 System Freezing


I built an i7 system several months ago, but have been experiencing intermittent freezing (screen is "stuck" on last image, sound stutters last output). Using default BIOS settings, I usually experience this after a few hours, but sometimes could go a day without the problem. The issue occurs most often during gaming (starcraft 2, world of warcraft, heroes of newerth), however I do not use the machine for anything else, and it has frozen from time-to-time simply sitting in windows. Upon tweaking BIOS settings, I can get the system to be stable for longer periods of time, the best uptime I have experienced is roughly 7 days.

CPU: Core i7 920 D0 (stock cooler)
Motherboard: Asus P6T Deluxe v2 (Bios rev 1003)
RAM: 3x 2GB OCZ GOLD DDR3 PC-12800 Low-Voltage Triple-Channel (spec: 1600mhz 8-8-8-24 1.65v)
GPU: EVGA Nvidia 9600 GSO
HDDs: WD 1TB Black, WD 1TB Green, ST 400GB (Page file is on the ST drive, OS on the WD Black. Have tried leaving page on OS drive but same results)
PSU: Coolmax CU-700B (700W)
Other: Logitech G15 keyboard, G500 Mouse, G330 headset (usb), Generic IDE DVD/CD RW
Monitors: Dell 2001FP monitor, Dell U2410 monitor (Both contain USB hub, U2410 has card reader built-in)
OS: Windows 7, Windows Vista (x64) (Currently running Win7 x64, but experienced same issue in Vista)

RAM settings on auto come up as 1333mhz, 7-7-7-20 1.5v, I manually change them to 1600mhz 8-8-8-24 1.66v per manufacturer specs.

The video card is using the upper (blue) PCIE slot, while the RAM are in the three orange slots on the mobo.

The following BIOS settings were changed in attempts to increase stability:
Differential Amplitude 800mV
Disable CPU and PCIE Spread Spectrum
Enable Load Line Calibration
CPU Voltage 1.25V
QPI Voltage 1.35V
Pll Voltage 1.88V
QPI 4800 MT/s
DRAM back-to-back CAS Delay 6 (default 0)
3N command rate

I also disable C1E, and Virtualization.

Lowering the QPI rate seems to have the biggest effect, although after doing so I did not remember to set the command rate or CAS delay back to their defaults and have been running with all three of those changes to test.

I do not believe the issue is software related, because I experience the problem on fresh installations of both 64bit windows vista and 7. I have attempted to install the OS from a clean format on both the WD 1TB drives but experience the freezing running from either.

I thought it could have been a heat issue, as the i7 core temps are reporting around 65 degrees C under load. The case has a 80cm fan blowing air in the front, and then another pushing air out of the back, with a third on the side of the case blowing air on to the memory. Running prime95 torture tests push the core temps to 100 degrees C but the system is still responsive so I am unsure if this is the problem area. I have also run Memtest on the three sticks of RAM without seeing errors, however they were tested at the same time; I'm not sure if that would give faulty results.

The Hard drives are all working flawlessly in other machines (the WD ones were purchased new for this system), and the 9600 GSO card runs without problems in my old system (uptime of months), so I do not believe these are problem areas either. That leads me to believe if my system is freezing due to a hardware defect, it lies in the RAM, motherboard, processor, or PSU.

Thanks in advance, any advice on how I could get the system to be stable would be greatly appreciated!
4 answers Last reply
More about system freezing
  1. 100C under load is way to high under load. It sounds like you haven't installed your HSF correctly. The easiest way to install the HSF is with the motherboard outside the case so you can ensure all four push-pins are fully seated. Another option would be to get a HSF that screws down and avoid the push-pins entirely.

    COOLER MASTER Hyper 212 Plus Intel Core i5 & Intel Core i7 compatible RR-B10-212P-G1 120mm "heatpipe direct contact" Long life sleeve CPU Cooler $29.99

    You POS Coolmax PSU isn't doing you any favors, either. A low-end unit will cause all sorts of stability issues.
  2. It only reaches 100C under Prime95 torture tests, normal load has been 65C lately (50C idle).

    I will re-seat the cooler and look into a screw down one.

    Any suggestions on a better PSU? If I can get away with 600W from a better manufacturer, etc. that would be great.
  3. Your CPU shouldn't be anywhere near 100C under Prime95 load. It also shouldn't idle at 50C.

    You don't need a 700W or 600W PSU for that system. A QUALITY 500W PSU would be plenty. What type of upgrade options are you trying to leave open? Here's a very nice 520W PSU:

    SeaSonic S12II 520 Bronze 520W ATX12V V2.3 / EPS 12V V2.91 80 PLUS BRONZE Certified Active PFC Power Supply $69.99

    If you really want a more powerful PSU then here's a few more good options:

    Antec TruePower New TP-650 650W 80 PLUS BRONZE Certified Active PFC Power Supply $99.99

    Antec EarthWatts EA650 650W 80 PLUS Certified Active PFC Power Supply $74.99

    CORSAIR CMPSU-650TX 650W 80 PLUS Certified Active PFC Power Supply $99.99 - $20 MIR

    Antec NEO ECO 620C 620W 80 PLUS Certified Active PFC Power Supply $69.99
  4. Thanks for the advice.

    The only near-future upgrade option I'd like to keep open is a video card, something along the lines of switching to a single Nvidia GTX 200 series card or ATI equivalent. If 500W is going to be adequate, I've got no problems going with that.

    I might pick up a Corsair PSU from a B&M store to see if that helps, besides re-doing the processor's cooler. I'll post my results once I have the opportunity to fix and test.
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