Memory v.s CPU

Ram, rails is ram bound not cpu bound in 95% of the cases I see.

Cheers- - Ezra Zygmuntowicz -- Founder & Software Architect -- ezra@engineyard.com -- EngineYard.com

More RAM, definately. And because it's a dedicated server, as long as you're not running any other CPU intensive processes at the same time the Celeron D should be enough... although if you can opt for a Pentium rather than a Celeron you may find the additional cache helps.

You've not specified which OS your server will be based on. I would assume the timeshare server is based on *nix. If the dedicated server is also *nix then 1GB should be sufficient, however if it will run Windows then you may find you need to add more memory.