Le Forgeron wrote:

Any suggestions on size of a PSU for a system with a i750 cpu and a
470GTX graphics card, say 4hds, dvd/rw, mobo and a pci soundcard?
Some overclocking expected for CPU and GFX (both air cooled).
System will never go SLI but a Pysichs card might at some point be
added.

Short of the pci soundcard, I have a Seasonix X-750 for that kind of
system (also 4 hard drives, 1 dvd/rw, 470 GTX, just another i7 model).
Run fine. No problem (X-750 is a 80+gold, if you take another PSU,
take that into account (loosing 10% of 750 can be important)

Back of 470 box says: minimum 550W with 38A on 12V rail.

I have a Corsair TX650W in the old system, maybe that is cutting it close
then. Maybe a good 750 as yours (I favour Enermax PSUs whenever possible).
Thanks for the info.