My friend bought a second R6850 and his current PSU (Model CM RS-500-PCAR-D3) is unable to handle it. he wants to upgrade to a better PSU, His budget is 7.5K . he wants to go for Corsair RM650 but I heard RM series is not that good.
His specs.
His specs.
*i.imgur.com/gri2jZH.png