As you are facing a performance issue with Photoshop, I suggest you have a look at this article and let us know if it helps.
Please tell us what error are you getting regarding the GPU, please follow the article below to troubleshoot GPU regarding issues: -
it has nothing to do with the settings (although i went through the link you provided, and went item by item to verify).
i am in the middle of putting together a small catalog at the moment, and am using photoshop for most of the layout/design. every spread that i have created, i can open from bridge and have it opened and ready in photoshop in approx 2-3 seconds (these are larger files... 17x11 spreads... 300dpi... roughly 90-100mb files). since the update, the exact same file is now taking 45-60 seconds to open. nothing else has changed outside of updating to macOS 10.12.4 (and subsequently, after this issue arose, making sure that CC was updated to the latest versions).
it directly has something to do with CPU usage. ive opened activity monitor, and when attempting to open one of these files, the CPU usage of photoshop spikes to 99% until the file is opened and editable in photoshop, then drops back down to 1-2%.
i have asked a friend with the same exact setup (he has less memory, but same exact machine) to open one of these files... he has not updated to 10.12.4 yet... there are no issues with his machine. it opens in 4-5 seconds, and cpu usage never exceeds 5%.
at this point, its fairly safe to say that there is some sort of issue with the latest version of Sierra. question is - WHAT?
I appreciate your efforts, could you try disabling the Font preview, Type > Font Preview Size > None
Restart Photoshop after disabling font preview and let us know if it works for you.
That had no effect - however... that started me thinking. I use FontExplorer X Pro, and remembered it had a plugin to intercept/activate font requests from photoshop. i disabled that, and the file flew open immediately.
So... the issue is the update has done something with FontExplorer, not photoshop.
Thank you for your help!
Glad you got it working, feel free to reach out to us for any future queries