The performance of Photoshop or your Games. Games are more graphic intensive than Photoshop. It you want to improve Photoshop you would be better off adding SSD, Ram and upgrading you processor.
thanks fir response - it's purely to improve performance of photoshop cc, it's not for gaming, I thought it should be graphics card to upgrade but am open to correction
Assuming you are talking about a desktop computer, what case does it use? Big gaming video cards like GTX1080 need a decent sized case just to fit them in.
What are the rest of your system specs? What motherboard. and how many PCIe lanes does it have?
Balance is an important factor with computer hardware.
The Photoshop graphics processor (GPU) card FAQ tells us what aspects pf Photoshop use the GPU. Try creating a really big document (up res an existing photograph to 30,000 pixels on the long side) and run a GPU intensive feature on it first with GPU enabled, and then with it turned off (you need to restart Photoshop after changing this). How much difference did it make? Come back and tell us so that someone with a nutter b@r$t@rd GPU can compare. It would be an interesting experiment for a lot of people I suspect.