Proxy Server 2.0

i am currently using proxy server 2.0 on an NT 4.0 box that simply performs logging. Meaning it doesn’t have two nics. I simply monitor and restrict web site content. However it seems to be getting slow. I did some perf mon on the box and the current average milliseconds/request is high – sometimes peaking at 100. I have about 2,000 users and I was thinking of a proxy farm. I just wanted some feedback on my assessment.