As a follow up to the previous post, here’s very subjective comparison of storage engine performance in 5.3.

Microsoft SQL Express. Clear winner. Fastest all around file-based storage option, while still being free. The only downside is that it requires a separate install.

SQLite. Runner-up. While almost matching ‘read’ speeds of SQL express in pure API tests, Sitecore client feels less responsive. Significantly slower on writes, which is most noticeable during the publishing process. Faster than firebird on the same ‘client responsiveness’ scale.

Doesn’t require separate installation, meaning that Sitecore Installer is all you need to get up and running. Due to nature of SQLite, performance might degrade when having large number of concurrent editors.

Firebird. The only file based storage previously existed in 5.x, the slowest choice for 5.3.