okay i just bought my 4870 from best buy.
when i installed it i was not pleased it got poor frame rates!, here are my specs...
amd athlon 64x2 4600 running at 2.66ghz
windows vista 32bit
2gb ddr2
apevia iceberg 680 watt power supply
visiontek 4870.
when i had my 8800gt 512mb installed. i would get around 25fps average.
now with the 4870 with the latest drivers, i get less than 19 frames per sec!!
please help me out!
I'm also betting the 4870 is having an identity crisis with leftover nvidia drivers. Drivers can be hard to fully get rid of, do some searches on the subject to make sure you get them all!
I think you have apoor power supply. Certified are recommended.
ATI Radeon HD 4870 System Requirements
500 Watt or greater power supply with two 75W 6-pin PCI Express® power connectors recommended (600 Watt and four 6-pin connectors for ATI CrossFireX™ technology in dual mode)
Certified power supplies are recommended. Refer to http://ati.amd.com/certifiedPSU for a list of Certified products.