Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
They have the same GPU, and a similar CPU, so yeah, I reckon they'd have similar performance for gaming. Both would be pathetic for new games, though. If gaming is your priority, get a 15" MacBook Pro or a 24" iMac with GPU, a home-built PC or a gaming console.
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.