Hi Monkey,

Thanks for taking a look. I always thought memory made a lot of sense but, here's my question. Why would both DIMMS perform fine individually in Memtest, but only fail when run in pairs? That seems strange to me.

Anyway, faulty RAM is a cheap fix but, just for posterity's sake, how do I test for undervoltage issues?

Thanks for all your help.

E.D. Wayne

First of all, if you haven't already, make sure this memory is on the motherboard's QVL. If it is, double check to make sure they are installed in the correct slots. These boards are very specific about which slots they can be installed on, especially if they are running dual channel.

If your overclocking, set your memory to default in BIOS to see if this resolves your problems. Double check your voltage settings from here too. Not sure of the model number memory you have, but the voltage seems to vary quite significantly with the XMS series. BIOS default is normally 1.8v, which might be too low.

I can see you've used CPU-Z. If you go to About > Registers Dump, it will create a readable text file. This file will contain the model of your memory, it's settings, and it is also useful for making sure your board is receiving the correct power. What may surprise you is that this particular PSU only barely meets the minimum requirements for this card, with no margin for error. I think problems are inevitable. The PSU, as far as I can tell has 4 x 12v rails, which supply 20 amps to each of them. The minimum requirement for these cards is 40 amps (2 x 20 amps)! PSU's do degrade over time (capacitor ageing), consume more power, leaving less for the rest of the PC. If this is the case, it may answer why your problems have slowly become worse over time.

System is in open revolt!

Mutliple BSOD's. Going to post minidumps while I've got this thing stable for a second. Will post back more details soon.

wayne,

I have edited your thread to something more descriptive, and relating to the issues you are experiencing.

Just in case you lose the thread, it is now titled Custom Built Rig Becoming Unstable

Okay, so now I'm confused. Couple things to note first:

System apparently DID NOT like switching the DIMMS to the alternate pairing slots. There are two blue slots and two white slots. According to the MB documentation, they should be interchangeable as long as you keep them in pairs. Apparently NOT the case. Anyway, switched them back to the original config and things appear stable....for now. Note, that's stable as in "not bsod'ing every 3 minutes." Still having the same issues as before .

As to the QVL: Monkey, the one you posted is for a different board. That's a P5N32 E - SLI. Mine is a P5N32 - SLI Deluxe. Interestingly enough however, when you dowload what is supposed to be the appropriate QVL from the Asus website, you get a QVL for a P5ND2 - SLI Deluxe, which is also a different board, and it doesn't even have a PC 800 list (which is what this ram is). So, in short, I don't know if my RAM is on the QVL or not.

What I DO know is that my RAM is Corsair Twin2X2048-6400C4. According to the very limited specs provided on Corsair's website, it was:

"Tested at latency settings of 4-4-4-12 at 2.1V"

What that means, I have no clue. Does that mean it's the voltage is supposed to run at, or is that an overclocked voltage? Currently, all my voltage settings in BIOS are set to AUTO. I can change them manually but, curiously, 1.8V is not an available setting for the memory. 1.85V is, as is 2.1V, but I don't want to get crazy with this stuff and fry my system.

So how should I proceed on that front?

Secondly, I'm confused about the PSU issue. I think almost every PSU I've seen is either a quad rail, dual rail, or single rail. And they're all 12V. And all seem to have 4-PCI express connections. So I guess I'm not sure where I'm lacking in this respect. But that's a bit out of my range of expertise, so any advice you might be able to give me would be very much appreicated.

As always, thanks a million for all your time guys. I really appreciate it.

E.D. Wayne

Ah, I get the PSU thing now. NM on that front. But, if it were a PSU issue, wouldn't it be more prone to reboots and shutdowns that just simple crashes-to-desktop?

Wait a minute....

Now I'm confused on the PSU thing again. Had to dig up my old reference manuals but W=V x A, right?

Thus, A= W/V

So, if the specs for the card list the maximum graphics card power as 204 W, doesn't that translate to 17 Amps?

Or am I totally off the reservation?