Ultra-D dying after ~1 year?

My system:

Opteron 146 CABYE O540 @ 300*9 @ 1.45v
XP120 w/ 120mm Panaflo U1A
DFI Ultra-D bios 623-3
2x512Mb OCZ Platinum EL rev2 @ 2.5-4-3-6
BBA x800 Pro @ 550/560 w/ ATI Silencer 4 rev2
OCZ Powerstream 520W
250Gb WD SE16 / 160Gb Seagate 7200.7
Lite-On 52327s / NEC 3540A / '89 Model M / Lian-Li PC-75

It's been running just like this for about a year. 24/7 Prime stable, never a hickup until about a week ago. Suddenly started to have weird problems, lockups, BSODs, etc. Then two or three days ago I was unable to start windows - would just reboot after the splash screen. I tried backing off my settings bit by bit with no improvement & now I'm at dead stock defaults just to get stable again. I can now Prime for 24hrs. but I feel like a dunce with all this good hardware (well, good for when I bought it) and no OC!

I tried running CPU @ stock speeds & voltage and slowly creeping up the memory, and tried the opposite - same result either way. This is what really has me confused. I've had hardware die before, but usually I can single it out. My voltages are good (3.3v reads a little low in the bios, but IIRC it checks good with my multimeter & doesn't fluctuate. 5v & 12v rails are DEAD STABLE. My temps are always a little on the high side - remounted the XP120 about a dozen times when I first put this rig together with no changes. I used to idle around 38C and max out at ~50C at the above. Now I'm idling about the same & maxing out in the mid-40Cs. Chipset usually runs just a tad hotter than the CPU with the stock fan running full all the time.

Can anyone think of a good way to isolate my issue? I don't have any other hardware right now to swap in, and I don't want to drop any $$$ now unless I know what the problem is. . .

I'll post again in a few min. with shots of my BIOS settings.

i would say memory or PSU if not the board, just a guess

Someone on dfi-street posted this:

"Well it could be the board dieing or it could be your on-die memory controller slowly dieing

You could drop to a 4x multi slap the ram on 1/02 then see where your max stable htt is (this will rule out the board)

If the board reaches a normal high htt for lanpartys (300htt+) then you can consider it ruled out

idk for some reason im really thinking dieing memory controller"

I thought that was a pretty sound way of testing, so after ~2hrs of Memtest w/ no errors I'm in Windows and about to start Priming for the night. CPU is at 300x4, RAM is at 150 (1:2) Everything seems fine so far. Maybe the board is fine & my Opty is crapping out?

your board is still at 300 and your mem controller is probably ok your ram though is running 150 instead of stock 200...

I bet its the ram

It's definitely strange that you get instability both when raising CPU and keeping memory at or below stock, and when raising memory and keeping CPU at or below stock. I'd still put my money on the RAM though. Almost every stability problem I've ever had could be attributed to dead/dying RAM. One time it was VERY difficult to find the culprit though, because both sticks of memory would pass Memtest86+ with no errors. Only Prime95 was able to find the bad stick of RAM after 1-2 hours of torture testing.

Take a stick out and see if it will run ok. If it crashes swap the sticks and try again. Its unlikely that both sticks would be going bad if its the ram. Your problem doesnt sound like a memory issue, but doesnt hurt to try.

Already tried every combination of single sticks in both orange slots - no luck.

I was able to Prime 24hrs. stable at an HTT of 300, so I don't think it's the board. I'm going to start slowly pushing up again with the new BIOS and cleared CMOS. I'll post back with results. . .

Tried to get back to a mild overclock & had no luck. Anything above stock settings craps out before getting into Windows. . .yuck.

So at stock settings you have no problems at all?

Yup, at least for now, stock settings are 24hr Prime stable. Part of my concern here (other than preferring my system run faster!) is that if I was able to run 2.7Ghz/250mhz for 9mos. and now I can only run stock, things will most likely get worse & not better in months to come. . .

WHen you started having problems did you check the leds on the back of the powerstream to see if they were all green?

Im more inclined to think its the opty and not the board now.

Oh yeah. The PSU's led's are all green. Voltage doesn't drop at all on the 12v rail when going from 0% to 100%. 12.27v before & after.

Sounds like a dying Opty to me as well... whats the highest voltage you ever put through it?