New Workstation build, needing feedback

Both the Corsair HX 750 and HX 850 go on sale frequently and actually are LESS than Silver and Gold 650 W PSUs. Two weeks ago, the HX 850 was $119.00 at Newegg after rebates which was a screaming deal. If you have time to watch for sales you can get them cheap.

A lot of people are specing their PSUs at 200 W over their needs but I don't do that personally because it can put you out of the most efficient range of the PSU which is usually %30 - 60% (on most PSUs the efficiency starts to drop at around 60% -70% capacity). I like to spec my PSUs at 50% more than what I need because it will always put my PSU at its highest efficiency and the units will run cooler and quieter. For my system, it will be always operating within the 30% - 50% capacity of the HX 850. That is my personal choice, some people disagree.

Keep in mind that the cost difference between the cheaper, less efficient bronze rated PSUs is rarely more than $40. The Corsair HX series has a seven year warranty, it is modular (it is much easier to build with modular cables), they are silver rated (the 850 has 91% efficiency at 30% - 50% capacity) and the customer service of Corsair is legendary.

For me it was a no-brainer and I went with the HX 850 and I am only going to run a single GPU (an ATI 6950). I am aware that a 650 PSU would carry the system but it would not be as efficient, as quiet and as cool. I only paid $144 for the HX 850 after rebates. Now you can get it cheaper. Actually the HX 850 will put out over a 1000W and remain stable and reasonably cool but its efficiency drops to 84%.