We wrote this whitepaper using the Performance Toolkit to test hardware configurations up to the 500 user level:
http://www.microsoft.com/downloads/details.aspx?FamilyID=3bf7ecda-7eaf-4f1c-bbfe-cae19bc8bb78&displaylang=en Read more: Dynamics CRM Benchmarking
http://www.microsoft.com/downloads/details.aspx?FamilyID=3bf7ecda-7eaf-4f1c-bbfe-cae19bc8bb78&displaylang=en Read more: Dynamics CRM Benchmarking