Redmine

Use case: updating 24 issues in a single project by changing target version through context menu. Redmine version is approximately two month old trunk/devel, running on Windows Server 2007 on a machine with 8 cores and 32G of RAM.

System-wide email notifications disabled through global admin settings, async_smtp:
952ms (DB: 281)

Email notifications for users who would have received a message disabled, async_smtp:
6708ms (DB:530)

Email notifications enabled for users, async_smtp:
6724ms (DB:437)

Email notifications enabled for users, smtp:
23587ms (DB:503)

I'm guessing Redmine does a short circuit on the global setting, but does a variety of message preparation and Issue inspection only to find 0 recipients in the middle case. I'll poke around this myself but I thought I'd report it in case there was anything obviously broken.

Will be updating to 0.9.x series soon and will repost findings. If you need any additional performance metrics/data, please let me know.