Advice - Video card and PSU combinations

[EnsignFodder]

I have two systems.

One with Dual 8800GT's (PNY-XLR8) and a Corsair 550W Vx
Once with single MSI 260 (stock speed) and a CORSAIR 620w HX

The question is, assuming all other things to be the same, would I be better off using the 620 in the dual card machine?

If so can you please show your work (like school) so that I can understand.

The two systems are similar (disks, wc pump, fans, mb) except for processor and ram configuration.

Thanks!

 

[mpilchfamily]

Both PSUs have plenty of power to support either system. There is only about 10A differnece between the 12V rails of the 2 PSUs. Doesn't matter which one is where. I beleive the GTX 260 actully pulls more power then the dual 8800GTs.

 

[EnsignFodder]

Thanks for the information and spelling out the what and why. So it really comes down to the modular PSU versus the standard and which works in which case.

Thanks again.