Finding a new VGA (650w / $200)

Aezritte

Honorable
Sep 13, 2012
10
0
10,510
CPU: X6 1055t
RAM: Corsair bus 1600 2*2
RAM: GSKILL bus 1600 4*4 (total 12 gb)
MOBO: Gigabyte GA-970A-D3
PSU: XFX 650w
OS: Windows 8.1

Budget = $200
PSU = 650w

I play skyrim with hd texture mods... my friend said >3gb would be great.

AMD HD 7950, 7870, R9 270, R9 270x, R9 280, R9 280x
NVIDIA GTX 670, 760

My main concern is that my psu is 650w. Please pick the best one. :)

ps. the "msi R9 270x gaming 4gb" really got my attention. is it that good?
4gb, is it really useable?

Thank you in advance, guys.