Since it is Christmas and I got some money, I was thinking about upgrading my graphics card because my current graphics card is really a disaster. I currently have Geforce GS 8400 256MB version, I think that Egyptians used it as a building material in the ancient times... actually I am pretty sure they were using it. Anyway, back to the topic. I have:
either of those card should be a vast improvement over your current card. The bottle neck in playing games etc. will be your RAM and possibly your processor: both are old enough to slow down the newer cards a bit: BUT you will still see an improvement. Here's a really good link on Tom's; take a look at the hierarchy chart second from the last, and see how various cards are "rated". AND the 5570 appears to be a better choice then the GT630 (with either GDDR3 or GDDR5). Power wise you should be o.k. with your power unit as long as it is a quality unit.