I have a Sapphire HD 7950 Vapor X and it pushes 600mhash O/C
Just bought another that is faulty due to artifacts in games from the bay for £100
Should push me to 1.2GHash
Also took the plunge, don't know why, but I can afford the risk of ordering 2 BPL units for £240 incl shipping. Never know when I will receive them, if ever, but at least I have some paypal time to revoke and think about.