In his “Musings on Reporting and Notification Services” blog, Lukasz Pawlowski takes a look at a lessons learned technical note from the the SQL Server Customer Advisory team.
The team was comparing scaling up SQL Server Reporting Services 2005 vs 2008. The bottom line is that SSRS 2008 was able to respond to 3-4 times the total number of users and their requests on the same hardware.
So if you’re facing performance issues with SSRS 2005 reporting with GP, help, in the form of SQL Server 2008, is on the way.
SSRS Performance and Scale
Install, Upgrade & AdminReporting & BI
Archived post from 2008. Dynamics GP and the links it points to have changed since; check current documentation before relying on version-specific steps.