memtest86 test #5 failures with 3 sticks of CMX512-3200C2PT RAM

[unprovoked]

Greetings...

 

I am getting memtest86 test #5 failures on my system. I am worried about this because I have been getting mysterious crashes with XP, and also started to see "Delayed write failures" for one of the hard drives last night. I haven't dared to boot into XP since that error -- I wanted to make sure my RAM was okay first.

 

MB: Abit NF7-S

CPU: AMD Barton 2500

PSU: Antec True380S

 

RAM: 3 sticks of Corsair CMX512-3200C2PT.

Two are marked XMS3202v5.1, 0503014-4.

The third is marked XMS3202v3.1, 0412008-2.

 

Notably, test #5 is failing *only* when I use three sticks of RAM.

 

It passes for each of the individual sticks in each of the three slots (9 tests total). It also passes when only two of the three sticks are present (3 tests total). It fails as soon as I add a third stick! Why is it failing only when there are three sticks? Is there something incompatible with the two different Corsair revisions I have?

 

I am not overclocking (166MHz*11). BIOS memory timings are set to "optimal" 3-3-3-7, but I have tried other timings like 3-4-4-8. The power supply controller is set to system default (2.6V for SDRAM, but I've also tried 2.7V and 2.8V).

 

Please help!

[RAM GUY]

What do you have the memory frequency set to?

[unprovoked]

Not exactly sure what you mean by memory frequency. The FSB is running at 333MHz, so I guess the memory frequency is 166MHz? Its running Mobile Barton XP 2500+, not overclocked.

 

There is also a mysterious BIOS setting for CPU FSB/DRAM ratio, which I have set to "auto".

 

Does this explain anything regarding the three sticks of RAM problem?