Earlier this week, Nvidia released a new set of updated drivers for their graphics cards, version 196.21. Usually driver updates are a thing to look forward to, with various bug fixes and increased compatibilities. However, this time around enthusiasts were in for a nasty surprise.
It appears that in their fiddling, Nvidia managed to break some of the overclocking capabilities normally available to users. Expreview did some testing with various common tweaker applications upon hearing reports of users losing their ability to overclock with the new drivers and came up with some unfortunate results.
Out of the four applications they tested, only one retained its full set of overclocking settings. Two of the most common tools, RivaTuner and EVGA's Precision tuner (version 1.9.0) both lost the shader clock setting. Galaxy's Magic Panel was even worse off, being rendered useless with all of its settings disabled. Only MSI's Afterburner application (V1..5.0 Beta 5) came out of the tests with all of its settings intact.
Upon learning of this new issue, EVGA has been quick to act. They immediately notified Nvidia and have since released a new version of their Precision tool, version 1.9.1, that includes a workaround for the issue.
So what is the source of this issue? TechPowerUp's resident GPU guru, W1zzard has posted saying that it seems Nvidia changed certain IDs in the NVAPI that were not supposed to be changed.