I tried 2 methods to give a little more juice on the 680L, artmoney and Rbby258 MORE voltz.exe, and the 2 work great.
Rbby258 MORE voltz.exe is more simple and give same results. It seems this tool works with cards equipped with CHL8318 voltage controller chip only.
On my card, with a multimeter, value 100 on GPU voltage gives 1.38v, 120 1.4v, 140 1.43v ...
I will wait my waterblock to really test but this little tool works great.
If you want to give a little more on your cards andres, seems they're are compatible. Worth a try.

all infos found here : http://www.overclock.net/t/1398725/u...ng-tweak/0_100