MrStanler

I just bought a couple of Diamond HD7770's, for my and my wife's computers, and I had to upgrade our power supplies as well.   450w is running just fine, including 2 hard drives and a DVD drive.    The cards are incredible as well, bumping up my FPS from 15 to 50+ in Lion's Arch.   Yes you do need a power supply with the 6-pin PCI-E connector, but the cards should come with an adapter for the 4-pin power connector.

Its likely that even a no-name 450 W is enough for a 7770. Under load, its likely your system with that card wouldn't actually be drawing more than about 250-300 W at the very most (the card itself only draws about 80 W). That 500 W number you're finding is an inflated recommendation that has to be made because AMD has no way to be sure what kind of mismanaged trainwreck of a PC the customer might try to put their card in.

I don't want you to push you to the 7770 if you're concerned and/or don't really want to spend the extra money. But just be aware that playing with low details at your native resolution is a whole different world of visual fidelity than having to scale up a low-res image. But if you're doing that already with your GT 520, you may be fine with it, and the 7750 would still do it a hell of a lot better.

MrStanler, on 10 December 2012 - 10:45 PM, said:

Modern video cards and modern motherboards really have no "incompatibilities" per se, they all use a PCI-e slot.

I am a bit concerned about running an HD 7750 with a 1080p monitor.. yes, you can drop the game resolution, but the quality sacrifice is usually enormous since you'll be scaling up a small image to a large screen. Its up to you, your budget is what it is, but even an HD 7770 would stand a much better chance of handling native 1080p with still very low power draw.