Nvidia announced the end of driver support for certain operating systems and some driver features in three separate support posts yesterday. The big news is the end of driver support for 32-bit OSes after driver version 390 comes around. Smaller notes include the upcoming discontinuation of driver support for the NVS 310 and NVS 315 business graphics cards, and the end of support for quad-buffered stereo features starting with driver version 396.
Nvidia says that drivers after the 390 branch will not install or work on 32-bit Windows, Linux, or FreeBSD operating systems. The notes also say that future feature enhancements and optimizations will not be rolled back into older driver versions. Nvidia says it will provide "low to critical" security fixes for these cards in driver branch 390 until December 2019 and "critical only" support until December 2021. Driver version 390 is apparently coming later this month, which isn't a big surprise given the release of GeForce Game Ready driver 388.71 earlier this week.
The business-focused NVS 310 and NVS 315 cards were built using hacksawed versions of the GF119 Fermi 2.0 graphics chip found in the consumer-targeted GeForce 510. The change in support status could mean that Fermi gaming cards may be reaching the end of driver support in the near future, though those cards aren't up for playing the latest graphically intense titles anyway. Individuals running 32-bit versions of the previously-supported operating systems will need to make a move to 64-bit versions to continue to receive driver support. The NVS 310 and NVS 315 cards were never particularly adept at playing games, but security conscious business users will need to upgrade eventually anyway.
The quad-buffered stereo features are related to professional 3D visualizations. The announcement page has more specific details about the nature of the features and the behavior that new drivers will take when the deprecated APIs are called upon.