Today I used Vim to edit a big file, about 1.5Gig in size. At the end of editing, Vim occupied 9.1G memory. Fortunately the machine has 64G. I was using visual mode to do column delete. I can't use cut and paste (Unix command line, not windows cut and paste) because I didn't delete whole columns. The whole editing session took more than 1 hour with most time spent waiting for commands to complete.