How much RAM does ISA Server use, and how do I change this amount.
By default ISA Server RC1 will use 50% of available memory for the RAM proxy cache.
To change this, open the Cache Configuration properties and click on the Advanced tab. Where is says, “Percentage of available memory to use for caching” change the number from 50% (which is the default) to something more like 5%. Now restart the Microsoft Web Proxy service and memory utilization will be greatly decreased.