790i Lock up issue

[skawful]

Here are my specs:
EVGA nVidia GTX 260 896mb
EVGA nVidia 790i Ultra SLi LGA
Intel Q9550 2.83ghz quad core
4 Sata II 250gb hd's in RAID-0 - with vista 64 ultimate
1 500gb seagate hd
800 watt power supply nzxt
8gb DDR3-1600 OCZ Gold

History: I had XP installed and randomly had freezing (total lock up with looping sound) at very random intervals could be just reading email and much more often when playing a game... I thought it was faulty ram - so i took out all sticks but one and that seemed to almost eliminate the problem... but still froze occasionally...

I just upgraded to vista and now it locks up constantly... it's still random but i can get it to freeze 100% of the time after putting the computer to sleep and coming back and playing a video...

I've tried changing the voltages on the ram (havent set the timings... no clue how to do that)... I've downloaded the latest drivers and installed the latest bios... then downgraded a couple versions and still the same problem... i've replaced the graphics card... same problem

tried with all 4 gigs... took out all sticks but one still same problem...

My best guess is that i have to replace the motherboard... I'm posting this in hopes that i dont have to do that... any advice would be greatly appreciated...

any help with memory timings would be very helpful also =]

thx in advance

 

[gamerk316]

Alright, I had this on my setup, and I finally fixed it by doing the following:

*Increasing RAM voltage (I'm using 1.85V at the moment instead of my recommend 1.7V)
*1:1 RAM-FSB ratio (resulted in a slight OC (9.5 multi) and underclocked RAM with better timings (from 1333 9-9-9-24 to 1066 4-4-4-(18?)).

I'm not sure which exactly fixed it, but I went from once a day lockups to two weeks stable (and counting!), so this did it for me. I'm not touching the settings again after getting it stable though...This seems like a common issue with the 700 series though...

Note, I also increased my NB voltage to 1.4V (from 1.1); that didn't fix the issue by itself but may have an effect combined with the above...