From Teamwarfare.com
Due to some serious performance issues with Sierra's latest Tribes 2 patch, I am not requiring that servers run the CRC checking until Sierra fixes the implimentation.
Please disable the CRC checking on your competition servers. If the next patch fixes the CRC checking performance, we'll require it at that time.
You can disable it by adding the following line to your server config:
$Host::CRCTextures=0;