Fair enough, but I've been on Linode's forums long enough to have seen dozens of people running 50 PHP processes with 128MB memory limit each, on a 1GB server shared with MySQL and a bunch of other crap. (It seems that 128MB is the new "reasonable memory limit" these days, since that's how much RAM it takes for PHP to handle photos from 8-to-12-megapixel cameras and smartphones.)