I know there are tons of threads out there that ask this question, but a lot of them seem older and don't have proper answers.
When rendering my files from Adobe Premiere Pro CC 2018, it always uses my CPU entirely for rendering the finished product. This takes a really long time, as I have an i5-6500 (Quad Core clocked at base 3.2Ghz), so files can take between their own length to twice the video length to render.
When I select to use the Mercury Playback Engine, which explicitly states it uses my GPU to render, I still see 100% CPU usage with the standard idle GPU usage I get (0-2%). Not only is it selected as my Renderer in ME, but it's also selected as the default Renderer in Premiere Pro's project settings.
Sony Vegas Pro, the competitor to Premiere/AE/ME, renders on the GPU moreso than Adobe's products do. If the answer to this question is "not all effects render on the GPU, at the peak end of 2017 mind you (not 1998), then I have to sincerely raise an eyebrow how only cutting a video's length by a bit can somehow render slowly or doesn't constitute as "available to render on a GPU".
Though, if anyone has an idea of what I may be doing wrong that can be troubleshooted, I appreciate any help I can get!
Edit: I realized that I forgot to give some vital information in this regard.
My specs:
Windows 10 (64-bit Pro)
Intel i5-6500 (Quad Core, 3.2Ghz)
8GB DDR4 RAM
AMD RX460
Adobe CC is installed on my boot drive (SSD)
Files are rendering to a 2TB 7200RPM HDD
I'm checking performance via Task Manager (It shows GPU usage when games are using it all the time)