Annoying memory problem

[sja]

Could use advice if anyone can think of anything...

This relates to 4Gb of Corsair Dominator DDR2 (2x2gb) PC2 8500 C5 5-5-5-15. Motherboard is a Asus P5Q-E running the latest BIOS.

The computer has been running fine since the end of April when it was built.

Over the last couple of weeks it's begun randomly crashing/restarting.

I ran memtest a few days ago, and all tested OK. I went on to try a load of other things, but I couldn't get to the bottom of the problem.

I tried memtest again today, and it's failing, consistently, at 42% of the first test - every time.

Either of the modules on their own test perfectly in either of the two yellow slots, but if the modules are tested together memtest always fails at the same place.

I've tried fiddling with the timings to no avail - leaving it on auto gives 5-5-5-18, setting manually 5-5-5-15 (and 9-9-9-28 as suggested by OcUK support) makes no difference.

I'm at a total loss - anyone got any suggestions before I throw it out the window?

Cheers!
Steve.

 

[sja]

I've tried the two modules together in the black slots and run into a lot of problems - memtest basically failed as soon as it started with a lot of errors on the screen.

I took that to mean that the board simply wasn't intended to have the yellow slots empty.

 

[sja]

Right, one step forward, and about 24 back.

It looks like the main issue here was memtest86. It doesn't like the BIOS setting for "Memory Remap Feature", which is enabled by default (so 64-bit OS can use all 4Gb). With that disabled memtest86 runs fine.

So, I grabbed memtest86+, and that runs an entire memory test perfectly, no errors.

I've set the voltage to 2.10 manually, and I've set the timings to 5-5-5-15 manually. All I can do now is wait to see if/when it crashes again, and work out what to try next. :S

Thanks for all the suggestions so far guys.