Mine hit XFX yesterday, waiting to hear on that resolution.
Some power 101 that I wanted to portray here:
Voltage * Amps = Watts
PCI-E Bus provides max 75W + 75W from 6-pin = max 150W available
PCI-E is supplied at 12V: 12 * 6.25A = 75W max
So, going from this statement from Tom's Hardware review of the 5770:
ATI rates the Radeon HD 5770 for 18W of power consumption at idle and 108W maximum board power at load.
The entire board would most likely run at what voltage? 12V is supplied via PCI-E Bus and communication is usually set at 1.5V
12V * _____ = 108W max
This would mean 9A ... hmm
Explains the single power plug pretty simple.
Also means that 4.5A would be drawn from both the MB and the PCI-E plug. This is only assuming that current is equally balanced from both sources.
Yes, I agree... this is FAR below the 40A that is being debated on Guru3D. My power supply puts 18A independently onto each PCI-E rail. Is it possible that the amp draw from the MB is attempted to become exceeded? Regulators on the mainboard should keep from overamp on the mainboard, but could this point to the issue?
*shrug* I don't know... I have tried gathering what I could with my amateur (at best) knowledge of this type of architecture.
ATI has been sketchy in what exactly is needed to the card... they generalize based off of power supply. If it says a 450W PS is the requirement, but your PC pulls 80% of that... doesn't leave much to the video card does it.
Are higher powered machines the only ones with issues? Is my i7 and p6t board the incompatibility?
*BIG SHRUG*