Corsair XMS2X1024-6400 Instability on Abit IP35-Pro

Hello

I'm hoping someone can be a machete to my intellectual thicket. I've got a problem with my 2x Corsair XMS2X1024-6400 RAM on an Abit IP35-Pro:

They're so unstable in windows. I've already RMA'ed one pair (They showed the same symptoms, but ultimately died on me) and got a new set, who are acting the same way. 10-15 minutes after windows boot, they crash hard.

- Manual voltage setting is at the recommended 1.9v, and i've tried stepping it up a bit.
- Manual timings are at 5-5-5-12 (i've also attempted 5-5-5-15).
- Both divider 1:1 and 2:3 pass memtest86+
- I've tried disabling EIST and C1E with the same results. Altho, the 2:3 divider with 5-5-5-15 timings and EIST/C1E disabled lasted the longest. 4 thread Prime95 ran for about 15 minutes.
- XMS2X1024-5400 are stable on this board with 1.8v
- Tried different dimm slots, so it doesnt seem like they're defective.

Does anyone have any idea what could be wrong? The XMS2X1024-6400 are on Abits compatibility list. I can't imagine why i'd have to raise the voltage when i'm operating at stock CPU speeds.

Any help appreciated!

Manual voltage setting is at the recommended 1.9v

Click to expand...

There is your problem. They need 2.10 volts

Model
Brand CORSAIR
Series XMS2
Model TWIN2X2048-6400C4
Type 240-Pin DDR2 SDRAM
Tech Spec
Capacity 2GB (2 x 1GB)
Speed DDR2 800 (PC2 6400)
Cas Latency 4
Timing 4-4-4-12
Voltage 2.1V
Heat Spreader Yes
Features SLI certified
Recommend Use High Performance or Gaming Memory
Manufacturer Warranty
Parts Lifetime limited
Labor Lifetime limited

@ohio
that would be true if he said they were XMS2X1024-6400C4's if you check what he listed C4 is not in there(XMS2X1024-6400). another thing is the cas timings he listed further proving its not C4's.

what the op now needs to do is manually set the timings with specced voltage. download memtest86 burn that to a cd. boot to memtest and run afew rounds of it on the ram. to make sure the ram is not erroring out, it is highly possible something is wrong with the ram.

Ohioviper said:

There is your problem. They need 2.10 volts

Model
Brand CORSAIR
Series XMS2
Model TWIN2X2048-6400C4
Type 240-Pin DDR2 SDRAM
Tech Spec
Capacity 2GB (2 x 1GB)
Speed DDR2 800 (PC2 6400)
Cas Latency 4
Timing 4-4-4-12
Voltage 2.1V
Heat Spreader Yes
Features SLI certified
Recommend Use High Performance or Gaming Memory
Manufacturer Warranty
Parts Lifetime limited
Labor Lifetime limited

Click to expand...

Hmm, the ram i'm using is TWIN2X2048-6400C5. They're 5-5-5-12 and on the RAM itself it says 1.9v.

Evilsizer said:

@ohio
that would be true if he said they were XMS2X1024-6400C4's if you check what he listed C4 is not in there(XMS2X1024-6400). another thing is the cas timings he listed further proving its not C4's.

what the op now needs to do is manually set the timings with specced voltage. download memtest86 burn that to a cd. boot to memtest and run afew rounds of it on the ram. to make sure the ram is not erroring out, it is highly possible something is wrong with the ram.

Click to expand...

Thanks for your replies, guys. I spent the better part of the night running passes in memtest86+ at different speeds, different voltages, different slots.

2 passes, dimm1+3 passed OK:
- Timings: 5-5-5-12
- voltage: 1.9

2 passes, dimm2+4, passed OK:
- Timings: 5-5-5-12
- voltage: 1.9

2 passes, dimm1+3, passed OK:
- Timings: 5-5-5-12
- voltage: 1.95

After the last test, i booted windows and it's been stable ever since. Originally , AUTO timings would set them at 5-5-5-15, but they're set to 5-5-5-12 manually now. Abit's later BIOS releases indicate better compatibility with "certain types of ram", but i don't know if the Corsair are included in this due to them being on their compatibility list.

Thanks again guys.

you need more then 2 passes, set it for what the ram is specced for and run it overnight.

Evilsizer said:

you need more then 2 passes, set it for what the ram is specced for and run it overnight.

Click to expand...

I'll get right on it. It does seem weird that they'd be passing memtests but be unstable in windows.

well one thing i would do is change the last set in the timings -xx to 14 or 16, i can make a difference. if your ram passes the only thing i can think of is to up the NB voltage a tad. what about the hd's, run scandisk on them. if you oced to much with the ram erroring out it can corrupt data to the HD, data from HD to ram then back to HD.

I haven't stressed the timings to the point where it would cause datacorruption, but i'll run some harddrive tests too.

i dont mean timings but if you push the ram past what it can handle. speed wise that can cause the data corruption i was talking about...

Oh, allright Well i haven't. They're even underclocked as i'm still running stock untill i work out these kinks. I thought you were talking about the chance of corruption if if the tRas is set too low compared to the tRCD and CAS.