PSU Headroom Question

[RobertDiffin]

I realize I'm using an audiophile term, but given a set list of components (not talking about possible O/C or sli, etc.) how much above the wattage should one look at for the PSU?

Specifically, when I enter my current components into PCPartpicker, and swap out my old 560ti for a pair of R9 280x's, it comes up with a wattage of 748.

Yeah, you guessed it. I'm sitting here with a nice 750 PSU (Corsair HX750 to be exact). Will I be safe?

 

[rolli59]

Yes you will be safe. Quality PSU that can easily deliver 10-20% more than its rated power.
As well here is a system with a single 280X consuming total system load less than 400watts http://anandtech.com/show/7400/the-radeon-r9-280x-review-feat-asus-xfx/20 and the peak gaming power draw of the second card is around 200watts http://www.techpowerup.com/reviews/MSI/R9_280X_Gaming/24.html

 

[sosofm]

http://www.guru3d.com/articles_pages/radeon_r7_260x_r9_270x_280x_review_benchmarks,10.html
After this article 750W are enough if don't try to overclock nothing.