This is my experience testing the latest Nvidia driver with my GTX660 card and Vegas Pro v14.
I while back I could not get the preview monitor to show anything except a black screen. After some forum reading and discussion I rolled the Nvidia driver back to v382.05 which has been working fine, but I could not (or was advised not to) set GPU to be ON in the Options. I remember doing some tests and rendering was no different with GPU on or Off.
I wanted to use an effect recently and I got an error I didnt have OpenCL support. So I did a bit of reading and found the latest nvidia driver for my card has some support for OpenCL.
A few days ago, I set a system restore point and installed Nvidia driver 385.41 which is the latest.
The preview monitor now works with the latest driver!
I set up a 1 minute video to render and here are the results. Computer details and some other notes at the end.
1 minute video of 3 clips 1920 x 1080
The first 34 seconds with colour correction and Glow effect
The second 4 seconds crossfade with no effects
The third 23 seonds with heavy film grain
Results of rendering to Youtube 1920 x 1080 25p
Control (no effects)
GPU on 00:54
GPU off 00:53
With effects on.
GPU on 1:00 (1 minute)
GPU off 1:45
Added Neat video to the 1 minute track.
GPU on 6:19
GPU off 16:00
Computer i7 3770 Dell Vostro
16GB RAM
Graphics card - Dell supplied NVidia GTX 660
Driver NVidia version 385.41
Windows 10 Pro, 64 bit
Temp file to SSD c:\
Clip source e:\ segate HDD
Render to d:\ seagate HDD
What else could have affected the operation? I have no idea but here is some possibillities.
Windows 10 updates
Davinci Reslove 14 installed since graphics driver upgrade but before render tests.
Any other software installed in the last 10 months that may have affected GPU operation.
Anyway I can't even remember what OpenCL effect wouldnt work and I havent found anything that doesn't work yet.
That's it, just a bit of info. I will be leaving the latest driver on and GPU turned on from now.
Merv