Some time ago I identified an issue that blocked OpenCl from working on cards with more than 2GB. Netkas took this knowledge and created a fix. LOTS of people tried to install the fix but as it was a bit fiddly and required following instructions TO THE LETTER there were many problems. Apple has finally decided to stop knee capping the better cards and with 10.8.3 there is NO LONGER A BLOCK FOR CARDS WITH MORE THAN 2GB !!!!! Yep, all GTX580 3GB and GTX570 2.5GB cards should now be able to work just fine with OpenCl apps with no additional fixes or messing about with hex editors. This applies to both EFI cards and non-EFI cards. Whew!!!!