Multiple sites on one server or one site per server?
I've hit a roadblock due to the fact that I don't know much about this problem so I'm looking to see if people with more experience can give me some advice:
What's better? I've got three sites, one gets 40k hit/day, another 15k, another 10k. They are not very well optimized but I'm working on that (adding caching, etc.). Say I could move all three sites to one very powerful server (2x Quad Core Xeon, SAS Drive, 2G RAM) or move each site to a separate "pretty-good" server (Dual Core Pentium D, SATA Drive, 1G RAM). All the other features are the same, OS setup, Fast CGI, APC/Cache::Cache, etc. These are Perl/PHP sites with MySQL backends.
Any advice?