IP35 pro v1.1 memory problems/ questions

[FSH42NA]

I'm racking my brains to try to figure out if I have a mobo or memory problem.

the components I'm using are:

Abit IP35 pro v1.1
E6850 cpu - stock settings
Scythe Ninja B w/ Scythe 120 mm fan
EVGA 7 800GT video card
Corsair XMS DDR2 PC6400 2x1gb // Adata PC DDR2 PC6400 2 x 2gb
Seagate 300gb and 500gb SATA drives
Samsung DVD burner
Corsair TX650 power supply

The problem is this:

Running Memtest 1.70, my Corsair 2x1gb sticks made 10 complete passes without error.
However, when I ran Memtest on the Adata 2x2gb sticks, they errored out on test#4 and #7 (not a whole slew, but errors nevertheless). I assumed that they were just bad sticks. Today, I decided to test them out individually in the same dimm slot expecting to find the bad stick. However, they each passed!

Is there something I need to do in the bios to get these 2gb sticks to pass in dual channel mode? Both sets of memory are designed to run at 1.8v and I made sure I set the bios timings per the manufacturer specs. Is it more stressful to run 2x2gb sticks vs 1x2gb sticks? I know that 4x1gb sticks require upping the MCH voltage.

Thanks in advance for your advice.

 

[Aisengard]

If more sticks requires upping the MCH voltage, why not apply that logic to your situation?

 

[FSH42NA]

Originally posted by: Aisengard
If more sticks requires upping the MCH voltage, why not apply that logic to your situation?

Thanks for the reply. I upped the MCH one notch from 1.25v to 1.29, but I still error out on test#4. I'm upping it to 1.33v and gonna try another run. What's the max voltage recommended here? I don't want to oc just run stock stable.

 

[Aisengard]

Well, the problem is definitely in the motherboard, though it's not necessarily a problem per se.

Did you try testing one stick in the other dimm slot?

 

[FSH42NA]

Yup tried a stick in the other dimm slot too. However, the problem isn't with individual sticks, but with 2x2gb sticks. 2x1gb sticks worked fine.

Looks like I found a solution though. Buff and MON over at the Abit forums, advised me to bump the Vdimm up to a minimum of 1.85v and mch 1.33v. Additionally, MON rec'd that I bump the tRFC setting up to 52. I adjusted the Vdimm and mch as advised and I finally passed (almost, I'm on test #8 now) test #7.

Wish me luck.
thanks for your advice.

 

[Aisengard]

Glad to hear that you fixed your problem.

 

[VirtualLarry]

I had a pair of SuperTalent DDR2-667 sticks that would reliably error out in the same place on the same test in Memtest86 when running in dual-channel, but would not show the error when run by themselves in single-channel.

 

[FSH42NA]

Well, my problem didn't get fixed till I changed my memory to some Gskill DDR2 PC6400 2x2gb dimms. The Adata would make 1 pass on Memtest without error, but would error out on the 2nd pass. No amount of bios tweaking would help so I had to RMA them back to Adata. The Gskill worked fine at stock settings from the get go. Ran 12 passes of Memtest without a problem.

So I just got a bad set of Adata. Adata has been good to me in the past so I'll consider them in the future, but Gskill will probably be my first choice from now on.