How much Power supply do I need?
How big of a power supply would my PC need if I had a I7 - 3770k overclocked processer, 1 tb hardrive, 16g 1866 ram, and dual (NVIDIA GeForce GTX 660 - 2GB - EVGA Superclocked - Core: 1046MHz - Single Card)? I have all of this in a computer right now with a 650w power supply but only 1 2g graphics card I want to know if you think I could run dual 2g graphics cards on the same power supply or should I get another?
Well, Most Manufacturers Recommend a 750W PSU just for Dual Graphics cards, but you must take into account all the extra drives you have as well as everything you have overclocked.
I would recommend AT LEAST a 800 Watt PSU or even higher. It's always better to have more power than you need, than starve your motherboard and other componets hungry of power!
-Hope This Helps!
Last guy is recommending way more than you need, but it is good to have some headroom.
For reference, my system, with only a single 670 right now, peaks at around 300 watts, so your well above what you need with a 750watt power supply with enough amps.
This power supply will be more than enough for you, and it's a good unit:
being that newer gpus use less power a 650watt as long as its a quality brand should be fine, i run a oc'd x6 and crossfire 6770 which use similar max power consumption as the 660gtx and thats on a 700watt corsair gs, which is never under load as the fan never spins up for any longer than 1min.
A 660gtx the non ti uses the pci-e lane and a single 6pin pcie connection which draws like 150watts max so id say if at all ur pulling 500watts under load thats guessing but 650 should be fine