No doubt that Adobe Photoshop is one of the best image editor tool out there rather there are lots of its alternative, it comes with lots of features and allows you to do lots of things. It has lots of Fonts supports, Filters and brushes to do everything you ever wanted to do.
Once you install Adobe Photoshop then to get your work easily you might download and install several plugins, fonts and so on, all of them loaded when you start your Photoshop and makes your Adobe Photoshop slow.
If you wanna make your photoshop fast then you can disable them which you are not using regularly, for this you can use a freeware tool, Adobe Photoshop SpeedUp.
It allows you to do :-
Enable or disable the plug-ins as needed
Do not load Adobe fonts CMap and Base
Do not load Photoshop Presets
Optimize and reset Maximum Memory Usage
Restore to original settings with a click of the Restore button at any time