Blender running at a crawl after NVidia update I can’t say exactly the NVidia update was the cause but several other people and I have experienced a problem with Blender slowing to a crawl in the last few days. If you are having this same problem and are running Windows 10 with a NVidia GPU go to this Blender URL for more info:
https://developer.blender.org/T50650
I got this auto update from NVidia 2/13/2017 which is when I started having the problem:
NVIDIA - Display - 12/29/2016 12:00:00 AM - 21.21.13.7654
Check your update history. On Windows 10 do this:
Select the Start  button, then select Settings  > Update &amp; security  > Update History (in the right hand column near the top in blue).
It looks like the problem has been solved for at least myself and some other people. I and at least one other person sent a bug ticket to NVidia. NVidia stated the auto update I received was a generic Windows update and not one from NVidia. They recommended getting the appropriate driver form this URL: http://www.nvidia.com/Download/Find.aspx?lang=en-us and follow the NVidia instruction for installing it. I did the Advanced install and clicked the button to erase all of the old drivers to prevent any conflicts. It worked great and I think my Blender is running faster. I also downloaded the HP driver for this card as NVidia recommends, but it was more than 2 years old. I’ll just keep it for a backup.
I hope this solves the problem for others.