Windows has so much graphics going on that by having a decent video card it takes away graphics processing from the CPU and frees up a lot of cycles.  Doesn't have to be a lot of money on the card, and good video cards have been hard to come by of late, but that should be changing with the crypto crash - hopefully people will stop making mining rigs and video card inventory will improve.  With just slogging out code in a text editor, you're normally not going to notice much.  And our IT girl just came by and upgraded my permissions!  I think I may be local admin now on my box!