Asus P5B-E - Memory Errors When All 4 Dimm Slots Occupied

[PJStyles]

I have recently been experiencing instability issues and decided to test my hardware. I tested each ram module individually by only putting one of the 512mb modules in the DIMM slots. Each module passed all tests in memtest86+. The ram I'm using is the OCZ Platinum OCZ2P8001GK rated at 4-5-4-15.

I've correctly set in the bios the timings for this ram including the recommended 2.1v via the manufacturer's website. As long as I have one of the dimm slots free, everything works fine... In other words, I can have 512mb, 1GB, 1.5GM and everything is great.

Once I occupy all 4 dimm slots I start to get memory failure in the memtest86+ under test #7 (Random Number Sequence) test and it happens instantly. I've tried adjusting the timings etc but nothing seems to work.

I'm running the most recent bios for my Asus P5B-E board and no luck there. Also noticed that the highest voltage it will allow is 2.1v so couldn't even try 2.15v or 2.2v although not sure that would be wise anyways.

Some suggest it's the memory controller but I'm seeing far too many people with various P965 chipset boards having the same issues when all 4 dimm slots are occupied.

Does anyone have any suggestions at all? I'm all ears!! Please help!

PJStyles

 

[Peter]

No surprise there - bus load is a major factor in signal quality. This means the more DIMMs you add, the slower must (yes must!) your timings and sometimes even frequency become for stable operation.

RAM that isn't even rated properly (like yours, with timings only achieved with a 20% voltage raise and under ideal conditions) really shouldn't be expected to achieve its "rated" performance in less than ideal conditions.

 

[imported_RedStar]

I have followed this a bit over on the OCZ forum.

OCZ has not tested for compatibility with 4 gigs ...you are only guaranteed 2 gig.

That said ..people report they can run 4 gig, without error, if they underclock their 800 memory to 667. The odd person says loose timings also work.