Microsoft has two patches available for Windows 7 users that are using the newest AMD FX-8150/8350 (Vishera) type processors which address and improve the processor scheduling/thread execution core which may or may not be an issue with Crysis 3. I know these have been around for awhile, however, I know several users that do not have them installed.
The only reason I mention this is because I am experiencing more than adequate performance with my eVga 670 SC 4GB GPU & FX-8350 CPU. I notice others with this setup that are having considerable difficulties achieving a decent FPS. I have seen ~ 50 FPS throughout the first two levels at least...with no 'rope' issues either.
Perhaps it's because I am using the CVar Configurator....I don't know....however, it can't hurt to apply these two patches.
1. KB2645594 - An update is available for computers that have an AMD FX, AMD Opteron 4200, AMD Opteron 6200, or AMD Bulldozer series processor installed and that are running Windows 7 or Windows Server 2008 R2
2. KB2646060 - An update that selectively disables the Core Parking feature in Windows 7 or in Windows Server 2008 R2 is available
1. http://support.microsoft.com/kb/2645594
2. http://support.microsoft.com/kb/2646060
Again, I am not sure whether or not this affects performance within the game if you have this setup. You can at least have a look at those KB notes and see for yourself.
Tim