[Zammy-Sam]

As Satcomer mentioned already: http://www.macosxhints.com/article.p...41&query=k750i
I don't think Apple should provide compatibility for new devices in their obsolete software as less as you would expect OS8 to support current gpus. They are working on their new software and it's their right to ask money for it. Otherwise there would be no motivation to work on a better compatibility for the rapidly growing hardware market. If you want to stay up to date with the hardware you will need to keep your software up to date too.