I finally wrestled this one to the ground.
Turned out that the power supply would kick off under load. Without a load, in bios for example, no problem. With a load on the psu, it would shut down. When I shut down all overclocking/ hyperthreadng and other advanced bios features, and reduced the number of active cores to 1, I could get it to boot and stay that way for 2-10 minutes. The system would post successfully every time regardless of the settings in bios, and then die on boot.
What threw me off was that I swapped the psu for another 1000 watt psu from my sons machine. That failed at the same place (boot), so i thought the new psu was ruled out as the issue. Must be that this four year old psu was no longer producing enough wattage? Had to say- but I thought because of this test the psu was not the problem! (See the windows 8 install problem below)
I tried everything. I thought I was down to the cpu, but I downloaded and successfully ran the intel ram test without error (in that 2-10 minute window before sudden death).
I can safely say I tried all options to get this rig to run, including buying different ram, swapping the mobo, changing the DVD drive, booting with and without the HDD, various sata connection options, etc, etc....
So I bought a new, platnium psu. bingo. The Coolmax psu cost me a few hundred bucks and 100+ hours of my time!
Personal opinion, not being a techie, is that a psu should have a simple light that would indicate a shutdown level fault. Since psu's clearly shut down under certain fault conditions,they should report. If a motherboard can have an effective Post routine, and various inboard lights and tests to steer you too a fix, a psu can also.
Hunt and peck is nonsense with this expensive gear.
I will also make some comments about the windows 8 clean install. Watch out for the boot sequence. During the reboot process necessary to install, the setup program was not properly assigning the windows boot loader as the default boot drive. Without this, the install dies, and the system shuts down. Took me two days to find some other poor fellow on the Microsoft web support site who discovered this issue,and used f8 to control the reboot during the install. unique to my config?
Also found a problem with nvidia's new 64 bit driver for the gtx 670. The install process does not properly uninstall the old driver before install the new one (310 I believe). So, guess what happens - fade to black. The fix is to boot to safe mode (not so easy in windows 8; shift - f8 and hope) uninstall the old driver, reboot, and install the new driver.
Lastly, asus is pitifully behind on publishing compatible ram with at least the sabertooth x79 mobo. For what we pay for these rigs, they can do better than no updates since I think November 2011. The corsair web site isn't much better, where the " compatible ram" seems to have some marketing influence. Go check it out, as of a few days ago it recommend only three of the many compatible memory offerings for this mobo.
The Microsoft support website for windows 8 is also less than helpful. A, I the only guy doing a clean install of windows 8? Seems like the knowledge base is pretty limited IMHO.
Lastly, while I am sure the features of Asus' UEFI bios are great for overclockers, for guys like me who simply want bulletproof settings ( when the "optimized defaults" are not the same as the minimal configuration needed to resolve problems). A "bare bones" config would be a nice option!
So my nightmare finally ended when I figured out each of the three reasons my system was crashing, and rebooting (without even a BSOD):
- faulty psu that onl failed under load
- windows 8 clean install with a faulty boot sequence mid-setup
- nvidia's 310 driver load in windows 8 does not correctly remove the old before installing the new. (Admittedly this one was easy to fix)
Sorry to be so wordy, bit I thought others might benefit from my experience. Also, please forgive my lack of grammar and typing skills - editor and altar boy were the only two jobs I ever had where I was fired.