Starting OSX 10.9 Mavericks, Apple introduced a feature called App Nap for power savings.

App Nap will have severe performance impact on large software such as Gazelle.

If you experience slow downs and delays, you can turn off App Nap for Gazelle with the following steps:

- Make sure Gazelle has been installed on the Applications folder

- Shut down Gazelle if you are currently running it

- Now locate the Gazelle icon in the Applications folder

- Right-click on the Gazelle icon and click Get Info

- Now tick the option Prevent App Nap

- Close the Gazelle Info window and re-run Gazelle