Currently,I get about 200 Mhash from a Radeon 5770 but was thinking of expanding to 2 5850s for my main rig and Power supply[650W] might just allow it.....only problem is there are practically no HD 5850's around under 170 US or they are completely sold out.I also have another rig where I can place the Radeon 5770 for more potential mining as my goal will be to eventually break the 1 Ghash barrier in the coming months even if just barely.
I was also wondering if anyone thought the
upcoming Radeon HD 7xxx series would improve Bitcoin performance judging from the speculation of a change from what is current Radeon architecture to a more like Nvidia-like Fermi architecture.