Memory management question

[Guest dodoherty]

I have been doing performance load testing of an application running in

remote desktop to a Terminal Server running on Windows 2003 Server 64-bit Std

Edition run. I load up the server with remote clients running the

application until I reach the capacity limits of the server. In my 32-bit

server testing the available physical RAM would usually get down below 100MB

before the first big working set trim would take place. On my first test

using the 64-bit server (with 16GB RAM installed) the first working set trim

took place when there was still about 3GB of physical RAM available. It

reclaimed over 8GB of RAM from the working set bringing the available RAM

number up to 11.5GB. I continued adding users and the next working set trim

took place when performance monitor showed I had 8GB of physical RAM

available. Does anyone know what's going on here? Why would it be doing a

working set trim with so much physical RAM still available? I have my page

file size set at 24GB (all allocated up front).

 

Any help is appreciated.