ASUS P6T7 WS SuperComputer - No POST, System Lock Up, Freezes

Lately I've been getting a LOT of BSODs, freezes, and lock ups with my system.

I posted in the appropriate section (Crashes, Hangs, and BSODs) and I've narrowed the problem down to the motherboard; the ASUS P6T7 WS SuperComputer.

I have four GPUs, the EVGA GTX-580 Classified 3GB running in 4-Way SLI and have had no issues until now.

It seems like when I have PCI-E slots #1 and 3 occupied at the same time, the system doesn't even boot (no POST, the monitor just goes to sleep). I am able to run 3-Way SLI and SLI with any of the other slots. The only issue again is if BOTH slots #1 and #3 are occupied together.

I've done a LOT of diagnosis and even did a FRESH install of Windows, re-imaged the system after the problem came back thinking it was a software/driver issue at first to no avail. No matter what I do, the same problem arises if both those PCI-E slots are occupied.

I'm also running 2 EVGA Power Boost modules to give extra power to the PCI-E lanes since the motherboard does not have an extra molex connector. This board has two NF-200 chips so it definitely is able to run 4-Way SLI; I've been running it since last October without a single issue. I even changed the EVGA Power Boost module (put in a new one) to see if that was the issue. However, the problem persists and I'm going to be calling ASUS tomorrow (Monday) to start an RMA.

Can anyone suggest anything else I should try before doing an RMA to see if I can fix this?

By the way, I've done most of the stress tests already; tested each GPU individually, tested each PCI-E slot individually (and in SLI/3-Way SLI as long as #1 and #3 are not occupied), tested the RAM with MemTest86+ for 7 passes with NO errors, tested the CPU with OCCT/Prime95/IBT with NO errors, reseated EVERYTHING on the motherboard (GPUs, CPU, RAM, all other I/O devices, HDD/SDD), and even checked the DVI-D cables for the monitors and used different ones (I'm running NVIDIA Surround with 3 monitors).

Thanks.

Solarstarshines said:

Honestly just seems that Board Can't do what you need it to do anymore

RMA the board would be best also i would look into a different board with maybe more power options

Do some research on what boards offer the best 4 way sli with no issues running Multi card set up has always been a headache

Also if they give you an RMA make sure you tell them to fully test the lanes

One more note you ever touch the PCI lantency ? set to high it will for sure cause issues most are set at 32/some like 64/ others like to crank it higher 128 also this does stress components much harder which might be making the slot work harder and can't keep up last ditch effort <---------------

How do I exactly do that? Is there a setting in the BIOS for PCI latency? I know that some people have said that for running 3 GPUs or more, you have to set the IOH voltage to at least 1.20V (from 1.10V default), but I always left that on "Auto". Never had issues with that before. However, I'm not sure about this PCI latency thing. I've never heard of it before. Would love to try that out! Please let me know how to do this.

Thanks.