Need advice on unrepeatable Memtest86 error with TWIN2X4096-6400C5

[The Gonif]

Hi everyone,

I put two sticks of Corsair TWIN2X4096-6400C5 into a Gigabyte GA-G31M-ES2L motherboard with an E5200 processor. Everything's running at stock speeds and "Auto" settings in the BIOS. Memtest86+ gave one error last night, so to find the bad stick I pulled a stick of RAM and ran a few passes. Everything checked out, so I swapped sticks and ran a few more passes, but everything checked out again! Now I've replaced both sticks and everything is fine so far -- it's on Pass #6 after 4 1/2 hours of testing.

What do you guys make of this? I feel leery of proceeding with the build after getting a memory error, but it doesn't seem to be repeatable! The only thing different today is that the two RAM sticks have switched slots from where they were last night. And I'm positive that both sticks were firmly seated last night.

Any ideas on how to proceed? Or is there a setting I can change to help smoke out the memory error?

Thanks!

[VorLonUK]

Re: Need advice on unrepeatable Memtest86 error with TWIN2X4096-6400C5

Your ram sounds like it's ok, yet it is on the threshold of creating the odd error due to your bios settings.

This is a very common issue and has been covered numerous times on this forum.

A couple of settings in the MIT section of the bios have a big impact on this.

Things to check and change:-

1) Performance Enhance = Standard (usually at turbo by default)
2) tRFC aka (Refresh To Act Delay) = 56 (usually set to a smaller value when on auto, based on the assumption 2GB total ram is being used)

If errors still exist:-

3) Increase DDR2 Voltage by +0.1 or if need be +0.2volts (1.9v - 2.0volts)
4) Relax main timings, to say 5-5-5-18

[The Gonif]

Re: Need advice on unrepeatable Memtest86 error with TWIN2X4096-6400C5

VorLonUK, thanks for your reply.

Based on your advice, I changed the Refresh to Act Delay from 42 to 56. The Performance Enhance was already set to "Standard". The RAM is rated at 5-5-5-18, and the BIOS did auto-detect it as that, so if Memtest reports another error can you recommend a more relaxed setting to use?

You know what's odd to me is that on the memory module itself it specifies 1.80v, but the BIOS reports that it's giving it 1.936v -- and there's no way to lower this since this motherboard only lets you increase voltage, not decrease it.

Also, what's frustrating (and this is probably due to being on the threshold, like you said) is that prior to changing any BIOS settings Memtest86+ went for 14 hours with no errors. Like I mentioned before, the only environmental difference from the failed memory test is that I had switched the positions of the two RAM sticks, so that stick 1 is now in slot 2 and stick 2 is now in slot 1. Is there any way that doing this could have changed things such that now the RAM tests out ok? It's difficult to feel comfortable with this setup when I can't even get the failure to repeat! Regardless, Memtest is now running after making that tRFC change and I'll post the results tomorrow morning.

Thanks again for your help!

[The Gonif]

Re: Need advice on unrepeatable Memtest86 error with TWIN2X4096-6400C5

Well, Memtest ran for many hours and the error did not come back, so hopefully the tRFC setting fixed it. Strange how I couldn't replicate the error, though. Anyway, thanks for your help!