https://stackoverflow.com/questions/18258561/pasting-a-huge-amount-of-text-into-vim-is-slow/79633075

I recently ran into this. I didn't realize that the swpfile slowed down pastes.

I was trying to paste 50kb of text in Vim, but it kept getting stuck and I had to kill -9 it.

But, then I ran :set noswapfile and the paste was instant! TIL!