Hi Guys, from Realhardtechx website is a psu calculator and a wattage usage chart
upto and including AMD 290(x) and Nvidias new 780 Ti.
Chart is in including one, 2,3 and 4 card configurations.
Remember these guys are conservative!!!!!
link
http://www.realhardtechx.com/index_archivos/Page362.htmI went from a 860 watt to x 1250 watt for future double card and overclocking.
This chart is truly a eye opener.
So $207 usd to protect a $1000 - $1400 usd investment is a no brainer and it is not overkill