I have a 400w, 12v1 - 18A, 12v2 - 17A power supply. It says that the loadlimit on the rails is 300w???
Will this run a HD4850? I know it is not the recommended PSU.
What PSU is it? If it is a good quality one, I think it ought to run it fine. If it is a cheap one, it might not work well, and possibly damage things.
Well, it's not horrible. If the rest of your system does not draw too much power then it should be o.k., but personally I would recommend purchasing a quality PSU of at least 450W. Well, you can get away with a 380W Antec Earth Watts or a 400W Corsair/FSP/ or PC Power & Cooling.
OK. Same question with a HD 4770. It is more efficient but still calls for 450w. Would I be "safer" with that card? And would the poosible damage give me warning signs?
I think they recommend a min of 450W or more for any GPU that requires a 6pin PCI-E power connector. the 4770 does use less power than the 4850, so you would be safer with that. If the card is underpowered, you'll probably know pretty quick because you'll probably get poor performance, artifacts and things like that if it is.