Avg load goes up after upgrading to Mavericks Just upgraded to OSX 10.9 Mavericks. Everything is good and shiny. However, when I open my iTerm to code, I notice that the performance is lower. If I run a uptime command, the average loading is always bigger than 1 even if I run almost no other user process. Before the upgrade, the number is usually near 0.

Anybody got the same problem? Any idea how to solve it (except rollback to 10.8)?
Finally found the culprit. I'm using zsh and the plugin vi-mode from Oh-my-zsh interacts poorly with git tools. Disabling the plugin made my zsh usable again in terms of responsiveness and reducing CPU load. 

There are conflicting reports whether Apple's git needs to be upgraded and you can follow that process at https://github.com/robbyrussell/oh-my-zsh/issues/2189

Still many thanks for all the people reply to the answer.