If you're planning on playing NFL Blitz, forget it.
If you're planning on playing Mortal Kombat, you should be good once you strip out the bloatware and unnecessary processes like anti-virus.
If you're planning on playing Galaga, you should already be good to go.

I have MAMEUIFX v0.146 (?) on an ~8-year old Toshiba laptop and it does pretty well IIRC, but I haven't used F11 to check speed/dropped frames on it.

Install the latest build of MAME and try the newest, most processor intensive game you're likely to play
If it bogs down, try an earlier version of MAME.

Scott