CCP Veritas has penned the first in a three part blog series about how the team is working to reduce lag in EVE Online. The first article deals with how the optimization of the game's missiles is an integral part of the project. The article comes complete with nifty graphs of before and after the work was deployed on Tranquility.

The direct missile optimizations were deployed to Tranquility on February 8^th with the Incursion 1.1.2 hotfix 7 in a partially dormant state.  In the days following, we tested the more dangerous aspects of the change on a select handful of systems then switched them on cluster-wide.  There appear to have been no issues, so hurray for that!

As for impact, I unfortunately can't point to any metric and say "this is because of the missile work".  We've got a cluster-wide CPU per user metric that's good at telling us when we've done something good in general, but it's very noisy depending on what the player population happens to be doing at the time, so it takes many weeks of data to be able to establish a reasonable trendline.  In the case of this change, there simply wasn't enough data before and after without other complicating factors to be able to say what the impact was.

Read more here.