If your PC has multiple graphic cards, you need to set Photoshop to use a High-performance graphics processor always. You can do them through NVIDIA Control Panel or AMD Radeon Software.

Restart Photoshop Properly set your Cache Levels If you've changed your Cache levels in Photoshop, you may have put undue strain on your graphics processor — most notably if your Cache is set to 1.

Given that only limited functions are GPU-accelerated in Photoshop CC, I would assume a faster CPU would be the way to go.

Photoshop CC 2015 tutorial showing how to create simple, but powerful 3-D text with deep, dramatic shadows. ➤ Get 15% off ...

4] Disable Graphics processor Disabling the graphics processor may cause Photoshop to render a bit slower since you would be disabling hardware acceleration.