Need help making my system stable again...

I've been banging my head against the wall for weeks... weeks... and weeks... so, time to ask for some help.   Necessary background...

 When I received my computer from DSO in October of 2008, it was OC'd to 3.54 ghz and was very stable.  I tweaked it a bit and got it to 3.83 without too much of a vcore jump, and I was happy, although I did eventually drop it back down to 3.54 ghz because I wasn't seeing much a difference anyway.  Then both of the RAM sticks went bad, and DSO sent me replacement sticks.  Ever since the memory swap, which I believe was last spring or summer, I've had nothing but problems, but I've been living with them for awhile.  After stumbling across an article on the memory I had (Corsair DDR3 @ 1333 XMS (full specs to follow), I realized that, for some reason, that this memory defaults to the incorrect voltage and timings, specifically, 7-7-7-20 @ 1.5v, instead of the rated 9-9-9-24 @ 1.7.  After changing the timings and voltage I am no longer getting memory errors, as far as I know.  But, however, my overclock was no longer stable so I set out on getting it back to stability.  (As an aside, about two weeks ago I got a second GPU and installed it in SLI... problems existed long, long before the second GPU was added, but who knows).

After fussing with it for quite a while, I reset the CMOS and started fresh, with default settings (with the exception of changing the memory timings/voltage to their proper values).  I ran MEMTEST to ensure the RAM was still good - it's passed two 8 hour sessions with no problems (each stick of the old ram failed within 20 minutes, regardless of the DIMM it was in).

I have done so much research, and have followed the guide from EVGA forum and linked by Kelly here.  Although I have yet to have it fail to POST, it either restarts within 3 seconds of ANY stress test (OCCT, Intel Burn) or freezes (80% restarts, 20% freezes).  Yet to  successfully complete a stress test of any kind since defaulting the CMOS.

All I want is to get the computer back to 3.54 ghz and stable.  It's still under warranty, but I do not believe this is hardware related (at least, not yet) so there's no reason to get DSO officially involved (although if any of them want's to chime in, that would be great :)).

Any help will be greatly appreciated.

Here are the relevant specs:
-EVGA 790i FTW mainboard
-860W PC Power & Cooling
-Intel Core 2 Quad Q9550 2.83GHz (frostbite liquid cooled)
-4GB DDR3 1333MHz Corsair XMS DHT @ 9-9-9-24, 1.7v
-2 x NVIDIA GeForce GTX 280 1GB (SLI)
-Microsoft Windows 7 Home Premium (64-Bit Edition)

And here are the current BIOS settings and the specs of my computer.  I can boot into OS, and do quite a bit actually, but restarts/freezes within seconds of any stress test.

BIOS Version: I790SZ12
**System **
CPU Freq, MHz: 2833.3 GHZ
FSB Reference Clock, MHz: 1333.3
CPU Multiplier: [8X]
PCle x16-1 & 16-2, MHz:  [100]
PCle x16-3, MHz:  [100]
SPPc->MCP Ref Clock, MHz:  [200]
nForce SPP --> nForce MCP:   [5X]
nForce SPP c-- nForce MCP:   [5X]
**Spread Spectrum**
CPU Spread Spectrum: [Disabled]
HT Spread Spectrum: [Disabled]
PCle Spread Spectrurn(SPP): [Disabled]
PCle Spread Spectrurn(MCP): [Disabled]
SATA Spread Spectrum: [Disabled]
**FSB & Memorv Config**
CPU Freq, MHz: [2833.3]
CPU Multiplier: [8.5X]
FSB - Memory Clock Mode: [unlinked]
FSB - Memory Ratio:
FSB (QDR), MHz: [1333.3]
Actual FSB (QDR), MHz: 1333
MEM (DDR),  MHz: 1333
Actual MEM (DDR), MHz: 1333
P1: [AUTO]
P2: [AUTO]
**Memory Timing Setting**
Memory Timing Setting: [manual]
tCL (CAS Latency): 9
tRCD: 9
tRP: 9
tRAS: 24
Command Per Clock: [2T]
** Advanced Memory Settings **
tRRD: [Auto]
tRC: [Auto]
tWR: [Auto]
tWTR: [Auto]
tFAW: [Auto]
tREF: [Auto]
tRFC:
**System Voltages**
CPU Core: [Auto - 1.25]
CPU FSB: [Auto - 1.1]
Memory: [1.7]
nForce SPP: [Auto - 1.3]
nForce MCP: [Auto - 1.500]
CPU PLL: [Auto - 1.5]
GTLVREF Lane 0: [Auto: -30mv] 
GTLVREF Lane 1: [Auto: +10mv]
GTLVREF Lane 2: [Auto: +00mv] 
GTLVREF Lane 3: [Auto: +00mv] 
**CPU Configuration**
Limit CPUlD Maxval: Disabled
Intel Speedstep: Disabled
xPPM Mode: [Native]
CPU Thermal Control: [Disabled]
C1E Enhanced Halt State: [Disabled]
Execute Disable Bit: [Disabled]
Virtualization Technology: [Disabled]
CPU Core 0: [Enabled]
CPU Core 1: [Enabled]
CPU Core 2: [Enabled]
CPU Core 3: [Enabled]


Sorry about the wall'o'text, but I wanted to make sure I included everything that might be relevant.



Edited by intellax - 25 Feb 2010 at 10:03pm

what are your sticks rated at? it will say on the side of the RAM

should not need to overvolt them at all, have you tried upping CPU FSB to 1.2V?

Edited by justin.kerr - 26 Feb 2010 at 9:28pm