APPROXIMATE PURCHASE DATE: This week.
BUDGET RANGE: 300-400
USAGE FROM MOST TO LEAST IMPORTANT: Gaming, BF3, Witcher 2, All the lastest and greatest.
CURRENT GPU AND POWER SUPPLY:
GPU: AMD Radeon HD 5870
PSU: Ultra 650W ATX
OTHER RELEVANT SYSTEM SPECS:
MOBO: Gigabyte MA790FXT-UD5P
CPU: AMD Phenom II X4 ~3.00 GHz
RAM: 4.00 GB DDR3
PREFERRED WEBSITE(S) FOR PARTS: I've really only used newegg
PARTS PREFERENCES: I like XFX, but no preference as long as they are dependable brand.
MONITOR RESOLUTION: 1920x1200.
ADDITIONAL COMMENTS: I am wanting to upgrade my GPU because i think thats where i would get the most performance boost, however if you suggest upgrading other parts that would give me more performance boost for less cost, i am open to suggestions. It is my birthday today so i am getting my setup fitted out
Try a 7950. The price dropped on them last week so you can get them for $399 now. Overclocked they can beat a 7970. I went from a 5850 to a 7950 and more than doubled my 3dMark score. It should also draw less power than your 5870 so if your current PSU can handle your current card it should be able to handle a 7950.
The 7950 will beat the 580 and stock it runs pretty cool. Personally I went with a Saphire OC Edition 7950 but there are alot of good manufacturers, XFX, Gigabyte, ASUS, Saphire, or even VisionTek (My last 5 or more video cards have been visionteks and never had a problem with any).