I am planning on upgrading my memory and I can get a gig of DDR 266 real cheap, but my system can handle DDR 400 even if my bank account really can't at the moment. How much of a difference would it be for gaming between the two different RAM speeds? A big difference or only a little? I'd hate to wait out, save for a couple of weeks, and spend the extra bucks for the higher speed RAM only to find out I wouldn't really notice the difference.