New ram, strange problems

[LeftyAce]

Hi all,

I'm attempting to upgrade from 1 gig of ram to 2. I ordered the identical ram kit from newegg to the one that's in the comp already, and when it arrived a few weeks ago, my comp started becoming unstable. It would hang seemingly at random (heavy ram usage, ie playing F.E.A.R or running many firefox tabs). I rma'd the ram, and the replacement has identical problems!

My diagnosis has consisted as follows:
Ran memtest for 9 hours, 13 passes with no errors. Tried different slots for different sticks of ram, tried 3 sticks, 2 old one new, etc. Whatever I did, in situations of high ram access, the computer would hang; mouse froze, etc, but with no BSOD and no reboot.

Right now I am running just the two new sticks by themselves and have had no problems yet. So my question is, is it possible that Windows does not like more than 1 gig of ram? Or that it doesn't like a change in amount of ram? Would it be worth the hassle of a re-install to see if this fixes it?

I don't think it's a BIOS problem, because the correct amount of ram is detected, and memtest ran fine.

Any thoughts/suggestions much appreciated!

[doctorgonzo]

I take it you now have four 512 MB sticks of RAM. Is that correct?

Are you overclocking at all?

[LeftyAce]

Trying to have 4 sticks of 512MB

No overclocking.

[flanzig1]

Double check the exact model number between the 2 sets. Corsair has a couple of different models that have different CAS and volt ratings.

[LeftyAce]

The numbers beginning VS512 are the same (VS512mb400)

I bought the ram using the same link on newegg.

[LeftyAce]

I double checked, and according to cpuz all the timings, etc are the same. Anyone heard of windows itself reacting poorly to a ram change?

[hitchface]

I doubt it would be a Windows reaction.

It appears that all of the RAM is fine, but running more than a gig kills it. Your PSU might not be handling it so well, not because it is a bad model but it might be faulty.

[LeftyAce]

How can I check the PSU? I have a PSU tester from compusa (checks a bunch of voltages, light on for ok and light off for bad), but presumably this thing doesn't load down the psu nearly as much as my system does :-) Is it still a worthwhile test? Is there a better way?

Thanks!

[hitchface]

Ok, I did a little looking about and found out some good info.

It is possible that you RAM is demanding too much from your PSU. You should be able to run a gig fairly easily, but as far as I am aware, the power consumption of 4 sticks of RAM can really tax the 3.3V rail on the PSU, which is why you see a lot of people with 2x1gig instead of 4x512.

I'll do some more looking about and see what comes up as far as definitive answers and a reasonable conclusion about the PSU.

[LeftyAce]

I've done a bit of research, and my psu manual says that over-current protection kicks in at 33 Amps for the 3.3V rail. Checked on corsair's website and found this link: the power requirement of a stick of DDR should be about 4.6 Amps, so I'm at half the power my psu can supply...Does this mean the psu is dying?? Other ideas? Thanks so much!

[hitchface]

Thats just the thing...it could be, but I'm not for sure so I am not ready to say that...I'll keep cruisin' about.

[LeftyAce]

Didn't think it was too important, as it only happened once, but I did get one BSOD:

Driver_Corrupted_mmpool

stop: 0x000000D0(0xB9FC0020,0x00000002,0x00000001,0x80542E45)

According to microsoft, this is caused by an invalid attempt to reference memory.....???

[glc]

Some motherboards just don't like 4 sticks of ram that don't meet certain specs. Try putting the ram on a divider to slow it down.

[LeftyAce]

Wow, I set the ram speed to 183MHz, and it's been working fine (running F.E.A.R and firefox simultaneously :-)

I'm curious though, how much does setting the speed down affect performance? Although obviously 2 gigs running at slightly below 1:1 sure beats running games out of the pagefile :-)

Thanks to everyone for your time and suggestions, and especially to glc for the solution!

N3WO

[glc]

On a Socket 939, you probably will never notice the difference.

[LeftyAce]

Cool, thanks.