Best GPU upgrade for my HP m7360n

^ You can even run an ATI HD 4670 on that PSU...It doesnt require any separate power connectors...
On the Nvidia side, you can get the Low Power 9600GT/ 9500GT...they are far better than that 8400...

I didn't think I would be able to run anything over a 8400gs with my lowly 19a. Seeing how this is just a temporary fix for an old pc untill I can afford a real gaming platform I am really nervous about spending 80 bucks on a GPU to have it not work. This specs on the 9600GT is saying minimum 350w with 12v/20a. I am only working with the 19a so I am really nervous about it going up in smoke after a month or two. The 9500GT says 18a so I should be able to push that ok. But it is weak on the gaming side. I would really like to be able to use a HD 4870 or 9600GT. Can anyone else vouch for these working on my PSU?

Check this PSU calculator...
http://extreme.outervision.com/psucalculatorlite.jsp

I could certainly say HD 4670 would work but certainly not anything above...
The 9600GT would be slightly pushing it as your PSUis old...

Thanks alot for the info. Probably going to go with the 4670 thanks for the suggestion.

Ok need a little more advice had my finger on the buy button for the HD 4670 512mb. then I read that it will take up two PCI slots due to the fan. I have 1 PCIe x16 slot and 3 PCI slots. (all taken up. I was going to just snap this one into the one PCIe slot but now I am wondering if it will work/fit. On top of that it says it needs 2.0 PCIe x16 slot. For the life of me I can't figure out if I my PCIe slot is 2.0 or what. Does anyone know for sure this card will work in my PC. Again its a HP m7360n. Also I have 3GB (3x1sticks) of DDR2 RAM. Should I go with 1GB card or 512MB? Thanks.

Ok well I guess I am going with the 4670 hopefully it will fit.

It will. the 4670 is a single slot card not dual.