The final issue is total wattage, and my question to anyone who knows.
If a card is limited to 126 watts (using SimpleMiner), where does the power for each card come from?
Is it a mix from VGA and the PCI-e riser? Something like 100 watts VGA and 26 watts from PCI-e riser?
Or, is the power to the card considered from the VGA connector, and they PCI-e is separate power.
If they are separate, then I'm doomed with a 1kw PSU.
That would be 780 watts (230x6) for VGA + 450 watts (75x6).
Can anyone confirm if the total GPU card power is split between the PCI-e and VGA, or are they unique and separate?
The power draw is ALWAYS split between the two - the question is how does the card decide to do the split, which seems to be a "we're not talking" thing from the card makers, but a lot of testing seems to indicate that most cards use the PCI-E bus power draw as a priority over the PCI-E power connectors.
It might also be, depending on the card, that certain parts are pulling from the bus (memory and fans perhaps) while the GPU pulls from the power connnectors - or even might be split by PHASE of the power conversion circuitry.