Quote Originally Posted by 'Naysayer',index.php?page=Thread&postID=109394#pos t109394
4gigs will work if it's fast, but you'll still lag a bit in Shattrath with only 4gigs. This means you'll need vista64bit to be able to use all of the ram and a decent motherboard as well.
RAM size & speed isn't the bottleneck in Shatt. Hard drive access times and transfer rate is. There are many people running 4GB very smoothly.

The problem of slowness building over time can be caused by add-ons that store data while you play.. recap/damagemeters/etc. Try resetting the data on those.