I upgraded from 1.0gHz/512mb RAM to 2.53gHz/2gigs of RAM. WOW! The new system is in-your-face faster, maybe 3x at least. I have a scene with 50,000 strands of Poser hair that took around 1/2 hour to render on the 1.0gHz system. The newer system handles the same scene in maybe 5 minutes. I think this is largely due to the extra RAM...the older system flailed away with the hard disc on this scene, while the new 2gigs-of-RAM system hardly accesses the hard disc at all. The Windows Task Manager reported a maximum RAM use of 1.4 gigabytes while this render was running. Most renders with one or two figures and a few props max out around 400 to 600 megs or RAM. So it seems like 1 gig RAM is about right, unless you are using lots of Poser hair or unless you are concurrently running some memory hungry program like Photoshop. The technical advantage of lots of RAM is that it keeps the system from using the hard disc for temporary storage when it runs out of RAM...the hard disc is far slower than RAM.