My Dell came with 8600 GTS and 375W power supply. According to internet the video card requires 350W power supply. Well Dell really didn't provide enough spare power did it? Unless the OEM video card is tuned down?
Well I just bought an Asus Geforce GT 440 that requires 300W. So the current power supply is plenty? Thanks.
You should be fine a lot of power ratings are more than you need generally. I run a 8800 gt 512 and i'm running it on a 300 watt. 8800 gt 512 quite old and a whole lot less power efficient then a gt 440. Like akshayghai29785 said you can run a gt 640 or 7750 and you would be fine. The only question is what processor are you running because you may run into bottlenecking if that is a old enough dell.