The SN500 uses a DRAM-less configuration, which has an impact on speeds but, as we all know, with the current pricing of DRAM modules, will help to keep the cost down. It also has an added bonus of reducing power draw which will be useful for small form factor laptops where every Watt counts.
Slow computer got you down? Maybe a hardware upgrade should be in your cards, if so this guide to the Fundamentals of Upgrading a PC is an invaluable read. PCSTATS Tips