I don't have retina macbook pro. but I recently bought samsung chronos 7 quad core i7 ivy bridge. it's equipped with Nvidia GT 640M (DDR5) 1GB. basically, it uses the same driver as 650M. I tried to install beta driver last week. so I uninstalled previous driver, and installed new one. but it didn't recognize and keep failed. so I rolled back to OEM driver. then I tried to reinstall beta in order to overwrite without uninstalling previous one. it kept saying 'can't find graphic card'. so I guess that I have to wait until official driver will be released. I don't want to screw it up. AMD driver had no problem as far as I know. but especially, Nvidia optimus driver seems to have problem after installing new driver. for example, it couldn't recognize dedicate graphic card and only works with intel HD 4000 integrate card. if you go to Nvidia forum, you will see a lot of people who has the same problem. it's not just new graphic but also old one sometimes.