We have a web service developed based on .net framework 4.0 and runs on Windows 2008 x64. The purpose of the web service is to emulate data abstraction layer communicating to the backend/downstream applications such as databases, external soap services, FTP, etc. Upstream .net apps will consume the services from this web service. Though the application is compiled for x64 code, we are hitting the memory wall @ 2GB and it becomes sluggish with falling response times for upstream apps (resulting in timeouts at peak loads). We also see '% time in GC' is more than 50%. We have 8 GB RAM and 4 CPUs. I am feeling that 2GB limit is holding it for better performance. What am I missing? What are the configuration parameters that are to be tuned for better throughputs? Thanks for any advise. Pingala