don't want to bash the party here, but looking at intel's datasheet i found the following figures for max voltage specs and
absolute max ratings (red):
VCC 1.35V 1.4V
VCCPLL 1.881V 2.0V
VCCD 1.575V (DDR3) 1.85V
VTT 1.095V 1.4V
VSA 1.2V 1.4V
remember this is intel spec. we are at xtremesystems here, so most won't even care ...
Batch is #3133B533
Passed 1hr, will try going up later.
http://i43.tinypic.com/dqocj6.jpg
Keep VCore higher than VCCSA for stability
Try to NOT have VCCSA less than VCore by MORE than 300mv for stability
45 and above appear to be problematic. 42-43 seem fine...though the issue is very random and I'm not sure I cycled enough times at lower frequencies to fully conclude. The longer between cold boots the more prevalent the issue, so it takes a long time to cycle. Most common occurence is when the system remains off overnight or all day.
However, good news, I applied some of the adjustments noted above a few hours ago, and I think the cold boot issue may be resolved for my configuration.
I applied the following settings for a CPU OC at 4.8Ghz with the ram at 2133mhz on UEFI 0803:
AI OC Tuner: Manual (changed from XMP or Auto)
Turbo Ratio: All Cores
All Cores: 48
Clock Gen Filter: 20UF (changed from Auto)
Memory Fequency: Manually set to 2133
Vcore: Manually to 1.42v (changed from offset mode or Auto)
VTT: Manually set to 1.25v (changed from Auto)
VCCSA: Manually set to 1.285v (changed from Auto)
RAM: Manaully set to 1.675v (changed from XMP of 1.65v)
PLL: Manually set to 1.95v (changed from Auto)
All other voltages and settings on Auto
Set DRAM timings manually to 11-11-11-31-2T (same as XMP but entered manually...all other settings on Auto).
I had previously set both vccsa and vtt to 1.3v (with all other settings on XMP and Auto except Vcore) which cut down on the occurence but did not eliminate the issue. The manual settings above appear more stable at boot and it's preferred with lower vtt and vccsa needed.
I have cycled about 12 cold boots now with 5-30 minutes in between and so far so good.
The 20uf setting made the most difference for me