I've run simple DirectRT subliminal priming experiment on a 2007 Thinkpad (Intel Core 2 Duo, 1.8 ghz, 2 gig ram) successfully. However, if I had too many programs running at once, reducing the computer's performance, the primes were visible. So it can be done with a fairly old (in computer years) laptop, just make sure you're not handicapping it with slow performance or incorrectly configured display settings.