I am in the process of creating my first assembled PC ever. This is going to be a 2600K based PC with reasonable OC air-cooled for 24x7 reliability. This PC will also drive upto 6 separate 1080p monitors (4 x 24", 3 x 23"); no gaming just charting.
I am converging towards using 2 HD5670 cards. These cards do not require a dedicated PSU connection and pull the power from the Motherboard.
The other option is to move up a bin and get HD57xx based cards which have a higher max power rating and require dedicated PSU connections. If and when I do decide to play a PC game, the higher rated cards with Crossfire will be nice to have.
From the point of view of a stable over-clock, which is better?
Do the card with the separate PSU plug draw ALL their power directly from the PSU plug (say 110W) or only draw the spare power (110W - 75W) from the PSU and the rest (~75W) from the motherboard?
And do two graphic cards drawing 70W each have an affect on MB stability when OCing?
I am planning to use the ASUS P57 PRO.