NVIDIA released a patch that enables PCI-Express Gen 3.0 interface mode for GeForce Kepler-based graphics cards, such as the GeForce GTX 680 and GeForce GTX 670, on Intel's Sandy Bridge-E HEDT (X79) platform. The patch is released on a use-at-your-own-risk basis, with adequate cautions and disclaimers to end users.
Back in March, NVIDIA's GeForce GTX 680, which was touted to be the company's first PCI-Express Gen 3.0 GPU, disappointed some, when it didn't work in Gen 3.0 mode on Intel Sandy Bridge-E (X79) systems (the only Gen 3.0-capable systems at the time). On what is currently Intel's most premium client computing platform, GPUs built on NVIDIA's Kepler architecture work only in PCI-Express Gen 2.0 mode.
NVIDIA removed support for PCI-Express Gen 3.0 on Sandy Bridge-E, post launch of the GTX 680, arguing that the platform while supporting PCI-Express 8 GT/s mode, isn't PCI-Express Gen 3.0 "certified," and hence to ensure the highest levels of reliability, support for Gen 3.0 mode was pulled. NVIDIA also assured at the time, that a patch would be released at a later date, which would re-enable Gen 3.0 on the platform. A little earlier this week, NVIDIA made good on its assurance, but with a few riders.
NVIDIA released a patch which has to be used along with the latest stable GeForce drivers, that forces PCI-Express Gen 3.0 bus interface mode for GeForce GTX 680, GTX 670, and other Kepler family GPUs, on Intel Sandy Bridge-E HEDT (X79) platforms. The patch would enable the GPU to take advantage of 8 GT/s per lane interface bandwidth, which could come handy, if the card is running on a PCI-Express x8 (electrical) slot, in certain multi-GPU configurations. The patch is a roughly 400 KB executable, which takes effect simply by executing it, and rebooting the system. The patch can be undone by simply running the same executable with "-revert" command-line argument.
NVIDIA does not vouch for the reliability of the patch, and cautioned people against using it, if reliability is paramount. Its use comes with no warranties. You use it entirely at your own risk. Enthusiasts willing to take the risk, and seeking to get what they paid for, can find the patch in the link below.