best AMD graphics cards for dell 375 watt PSU - I need display port and 2560 x 1440 res

[petebryn]

As above described, I have an elderly (5/6 yrs old) Dell 9200 desktop with 375 watt power supply. It seems that changing Dell PSU'S is a right pain, so I'm sticking with wot I've got there. I want best poss video - 2 screen max, inc Dell U2711 with 2560 x 1440 res. for streaming movies etc. I've tried AMD 5770, but tho 1 screen works ok, it cant handle the U2711; my other thoughts are the AMD 7770, 7750, 6670 in decreasing preference. I know I'm trying to push it a bit, any thoughts U techy guys out there ?

 

[DjDafiDak]

iam thinking you well get away with a 7750, since dell probably under rates their psu and you acttualy have a 400 psu( and even if you dont, a decent 375 watt psu is good enough for a 400 watt gpu, in reality).
get the 7750, you psu isnt strong enough for 7770 which requires 500watt.