One of the things you can do to improve performance on your TMG firewall is to reduce the amount of logging. And one of the best places to look to reduce your logging is at the System Policy Rules.
Check out this article that includes scripts that can help you turn of System Policy Rules logging at:
HTH,
Deb
DEBRA LITTLEJOHN SHINDER
MVP (Enterprise Security)
“MS SECURITY”
[email protected]