Also thanks for the reply. I currently am on a very strict budget so I thought the 5850's woul be good as with two of them I may get 700 KH/S for around $200 is this good or?
I think 5850 is good value for BTC mining. It is similar in performance to 6950, but is much cheaper. But when we have to move to LTC mining at the end of the day due to ASIC, then 6950 is better because it has 2GB memory.
My 5850 has hash power of 367 MH/ (928/170, core/memory) compared to 7950's 600 MH/s. The cost of 5850 is $100, while 7950 is $300. But you need two PCIE slots to accommodate two 5850. For BTC mining, it draws much less energy proportionally to 7950 as it has just 1 GB memory instead of 3 GB.