More RAM will make a big difference on 64 bit.

>If RAM will make a big difference, then I will easily and gladly go to 6GB or 8GB. In the big scheme, it's a small price. I had my last XP box for 5 years. Plan to have this one that long too, and I won't skimp over a few hundred bucks on something that will bring me daily (hourly) benefit. I work on this machine 80% of my work day.