Run GPUSniffer.exe in a CMD window and show us what it says.
Here is my GTX 680 with CC 2017 on Windows 10
C:\Program Files\Adobe\Adobe Premiere Pro CC 2017>GPUSniffer.exe
--- OpenGL Info ---
Vendor: NVIDIA Corporation
Renderer: GeForce GTX 680/PCIe/SSE2
OpenGL Version: 2.1.2 NVIDIA 375.63 126.96.36.19963
GLSL Version: 1.20 NVIDIA via Cg compiler
Monitor 0 properties -
Size: (0, 0, 1920, 1200)
Max texture size: 16384
Supports non-power of two: 1
Shaders 444: 1
Shaders 422: 1
Shaders 420: 1
--- GPU Computation Info ---
Found 1 devices supporting GPU computation.
CUDA Device 0 -
Name: GeForce GTX 680
Total Video Memory: 2048MB
C:\Program Files\Adobe\Adobe Premiere Pro CC 2017>
What version of driver are you using?
Above you can see my driver: NVIDIA 375.63
Thanks much Bill. Looks like I made the mistake of trusting Windows to update the driver. When I went to NVidia's site directly I did discover that the driver was out of date. I updated to the latest version and that seems to have solved the issue.
A follow-up question if I may...
Is there a "sweet spot" with respect to how much improvement one can expect as they move up too higher-end graphic cards with more VRAM? I'd be willing to upgrade if I thought there would be an appreciable increase in performance.
Well it depends on your media and what effects aqd features you use. Check your usage with GPU-Z and see how much GPU load you are typically seeing and check memory usage. If you are using 4K media you probably would benefit from more video RAM. I really like my new GTX 1060 SC 6GB (EVGA 06G-P4-6163-KR) for around $260 is a great step up, It overclocks the Memory Clock easily and safely to get great CUDA performance.
So for your own workflow, if you went to something like the GTX 1080 which seems to cost over twice as much, how much do you think that would affect your overall processing performance-- all other factors being equal? I get the feeling, rightly or wrongly, that there's a point of diminishing returns if one keeps throwing $$$ higher end cards...
For your older CPU I would never think of a high-end GPU, If I could afford a GTX 1080 I would be able to give you a positive answer, but I decided after testing one overclocked GTX 1060 that two $260 GPU's was a better than one $630 GTX 1080 SC. It would not be one iota better. How much GPU acceleration are you really using? I only bought the second card as an "experimenter" to give factual answers to questions like yours.
I figured it out. At least for me. I have an AMD R9 270X and an Intel Integrated Graphics. Turns out PP CC 2017 could initialize the Intel card. I realized that by using the GPUSniffer.exe. Then I simply went into my BIOS and disabled the Intel Graphics Card. And ta-daa, it worked. Hopefully it will be a solution for you guys, as well!
All the best!