There one little thing you can do. If you have photoshop opened, press CTRL+ALT+DEL. This will give you the task manager from Windows. (If you use windows, this doesn’t work for a Mac as far as i know.)
Go to the list with all the processes that are running. (don’t know the english word for it, i have a dutch windows)
Now scroll down to Photoshop.exe. Right-click on it, choose Priority and choose high. DO NO CHOOSE REALTIME! It will make your computer crash. If you choose high, it will make photoshop faster.
Hope this helps,
Michiel Koers