Just open the cuda_supported_cards.txt file from the most recent version of PR and you have the current list, including the GTX 680.
To see which cards from the 6xx series work, go to http://ppbm5.com/DB-PPBM5-2.php and select Video card, GeForce 600 series and you will find 45 systems using the 680, 670 and 660. Even 1 system with the 690, but with a very disappointting result, especially with the price of that card.
Does ppbm5 keep track of OS and nVidia driver version? I recently upgraded to Windows 8 and now the OpenGL driver crashes constantly with PP CS6. Based on other posts, I suspect it may be a problem with the later nVidia drivers, but it would be good to know what drivers the many ppnm5 users are using.
Good of you to mention that. No, PPBM5 does not have info on driver versions and the like. For the new PPBM6 test I am working on a new way to submit results. It is all explained here: http://ppbm7.com/index.php/instructions?showall=&start=1
If you follow these instructions about Speccy now, you can open the Graphics section to see the driver version in use. So I intend to have those data about driver version, as well as lots of other data that can be relevant, available in the new version.
Thanks for this question. It is very relevant to our script to parse out the Speccy results before submission.