Can no longer run RAM at overclocked settings

[Soulsink]

In June I bought a bundle from Overclockers, containing:

Abit IP35 Pro
Intel Q6600
Tuniq Tower
Arctic Silver
2GB OCZ PC2-8500C5 1066MHz RAM

With the bundle came the handy oc instructions which instructed as follows:

CPU External Clock: 367MHz (272MHz stock)
DRAM Speed: 1:1:25
PCI-E Clock: 101MHz
CPU Core Voltage: 1.4525V (there is no option for this in the BIOS so I'm running att 1.45)
DDR2 Voltage: 2.2V
CPU VTT 1.2V Voltage: 1.27V
MCH 1.25V Voltage: 1.37V
ICH 1.05V Voltage: 1.15V
ICHIO 1.5V Voltage: 1.55V

C1E and EIST Functions are both disabled.

I ran on these setting until approximately 3 weeks ago with no issues whatsoever. Then all of a sudden I started getting BSOD events, random system locks and resets/power offs.

I used parts from another PC to trouble shoot all the peripherals until I was just left with the core components, cpu, motherboard and memory. Eventually the memory just died and to make matters worse, I got a crash when I was trying to update to the latest bios. I got a new bios chip from ABIT and that board works fine now but during the wait I bought a new board and new memory, exactly the same models as I was running before.

I installed the new board and memory and the machine ran fine for a few hours at clocked settings until I, again, started getting BSOD errors. I decided to run the windows diagnostic memtest on all four modules - each of them passed when run on their own, but everytime I ran two modules i.e. 2GB the memtest failed citing errors in my memory.

I then reset settings to default and ran memtest on the modules, two at a time, and they passed.

Now I'm perplexed. The modules must be fine. Two of them are brand new today. The BIOS settings are exactly as laid out in the Installation and Overclocking Instructions given by OCers and these settings worked fine for months. From my admittedly limited knowledge base I can't figure out how they would suddenly stop liking those settings.

Just to clarify, I tested with another PSU, GPU, disconnected all peripherals etc. I did a full format on my HD, although since sometimes I couldn't even boot to BIOS I was pretty sure it was fine. The only thing I am wondering is if there was something in one of the BIOS updates which changed some settings and is causing these failures.

Or is it possible that an issue with the CPU??? Please help. I'm that ****** off I'm considering buying a laptop! oO

p.s. I can email/upload dxdiag/minidumps etc. on request.

Edit: forgot to mention, timings are 5-5-5-15

 

[decto]

There are a couple of options.

Check to see if the memory is set to 1T or 2T ... not should be 2T

Also if my basic maths is correct, your 1066Mhz memory is clocked to 1180MHz and as overclocking is always pot luck it might not be stable.

This can be tested by reducing the timings at the current speed eg 6-6-6-18 or using a different, higher ratio for Dram Speed to drop the speed down.

A different BIOS can have different timings and affect a once stable OC.

AD

 

[Soulsink]

It definitely seems to be an issue with the board or the CPU. I just plugged the RAM into an old system:

ABIT Fatal1ty AA8XE
P4 3.4GHz

and ran a memtest and it passed fine. My 3dMark Vantage graphic scores were higher too (put the same BFG 8800 GTS into that system) which is weird. The CPU test scored my Q6600 in the range it should be but on my IP35 Pro system my GPU scored 3200 - pitiful. On the Fatal1ty set-up my P4 also scored in the range it should but my GPU scored 6000. Both systems are running the same install of Vista x64 Ultimate.

I'm going to run some more tests, some 3dmark06 tests too. I could try flashing back to an older bios but since my system is so unstable I'm a bit worried about doing that. I'll post update later this evening.