[wp-hackers] Running several WordPress sites on the same server

[Simon Dunton - WP Sites]

There is a pretty big performance gain to be had from using the PHP APC opcode cache in terms of page load speed and requests per second. If you run that on a site with 100 separate WordPress installs that's potentially going to take up considerable RAM (lets say 30MB per site which could add up to around 3GB)

If all 100 sites shared the same core codebase than you might be able reduce this to 5MB per site (I'm plucking figures out of the air here, it depends on the themes used, plugins etc). This would work for multisite and should work for simlinks although I'm not sure if that's the same for both hard and soft links.

Then you've got the disk space benefits.

Also it's also much easier to keep track of one WordPress core instead of 100. By keep track I mean keep the core files in a local git repo so that you can track any changes made by a hack/virus etc.

So, many positives to running multiple sites from the same codebase, definitely worth investigating and I do hope you report back with your findings.

Simon