Debian pulled in 375.39 on testing recently and I noticed most of my games now have strong FPS fluctuations and there is stutter. Specifically Mad Max makes it very noticeable (drops to ~15 fps every 2 - 3 seconds and never manages anything like 60+, it seems).
I then tried a clean Ubuntu 16.10 install with 367.57, there performance is flawless and there are no slowdowns or stutter. Then I tried 375.39 on Ubuntu 16.10 as well, and there is the same degraded performance and stutter. Victor Vran can perform up to 50% slower than with 367.57 and this is reproducible on both Debian and Ubuntu, on a GTX 960 and a 1060.
There are others noticing this as well, I have a thread on Reddit.
I did some benchmarks. Disregard earlier claims that Tomb Raider tests 30% lower. It’s just choppier – i had the wrong setting for TressFX when testing on Ubuntu.
I believe this could point to an issue in Nvidia drivers 375 and higher, possibly also something related to changes in kernel 4.8 or 4.9, that can reduce performance by as much as 50% in some games. The last reliably fast driver I can run on kernel >= 4.8 is 367.57. It might only affect Z77 based i5 systems (because that’s all I have). 370.28 runs well on kernel 4.8 too, at least.
Update 2017-03-14: I tried 378.13 on Debian and it still has bad performance. 367.57 can no longer be built on Debian (perhaps because it doesn’t fit kernel 4.9).
Update 2017-03-15: Tested with Debian 8.7.1 so I could have the older 367.57 combined with Debian. Good performance all around. So it might be something between kernel 4.8+, the Z77 chipset and the newer Nvidia driver that is messing things up.
Update 2017-03-19: Tested it all on a GTX 960 with Ubuntu 16.10 and Debian 9, added some video capture and screenshots. Tested on Steam OS 2.0 with the GTX 1060. Links and results are in the spreadsheet.