One CSP Management Server can support thousands of agents. Server capacity will vary on a number of variables (agent polling interval, how events are transmitted, number of rules triggered with logging enabled, network bandwidth, etc.). With those caveats, here are a couple of example configurations we've suggested to other customers:
For customers with 10,000 agents:
Two application servers – (dual processors with 4 GB RAM and 2 NIC cards)
Database – 64bit dual processor with 2 -4 GB RAM and 8 15,000 RPM SCSI drives (minimum 40GB drives). For production, add another identical system to create a Microsoft Cluster environment for failover.
For 40K agents:
Three to four application servers – (dual quad processor 4 GB RAM with 2 NIC cards)
Database – 64bit Dual Quad CPU with 8- 16 GB RAM and 8 15,000 RPM SCSI drives (minimum 70GB drives in storage array).
For production, add another identical system to create a Microsoft Cluster environment for failover.
For 40K or 40K+ agents:
Deploy multiple application servers for every 10-15K agents. Judicious use of real-time event logging and bulk event file transfer features provides optimum use of available resources and best performance characteristics. Configure policies with actionable events to use the real-time method, and use efficient bulk logging mechanism for capturing/ recording voluminous events, such as, audit, forensic, and regulatory retention.
Refer to the Planning and Implementation Guide for further scalability information.