Um, speak for yourself. I ran Tor on 100 MBit switched Ethernet for a while, and it was very visible. I now run it throttled, and it behaves well -- because it's not written in Java.
Do you need TOR on your 100MBit-LAN??? Or do you have a 100MBit internet-connection which is saturated noteworthy with TOR-traffic?
I think it would be a terrible idea.
But it's theroretically possible!