Hello,
The following items are general answers to common system-performance questions. The performance of ACS in your network depends on your specific environment and AAA requirements.
•Maximum users supported by the ACS internal database—There is no theoretical limit to the number of users the ACS internal database can support. We have successfully tested ACS with databases in excess of 100,000 users. The practical limit for a single ACS authenticating against all its databases, internal and external, is 300,000 to 500,000 users. This number increases significantly if the authentication load is spread across a number of replicated ACS instances.
•Transactions per second—Authentication and authorization transactions per second depend on many factors, most of which are external to ACS. For example, high network latency in communication with an external user database lowers the number of transactions per second that ACS can achieve.
•Maximum number of AAA clients supported— ACS has been tested to support AAA services for approximately 50,000 AAA client configurations. This limitation is primarily a limitation of the ACS memory.
System Performance Specification.
http://www.cisco.com/en/US/docs/net_mgmt/cisco_secure_access_control_server_for_windows/4.2/user/guide/Overvw.html#wp827669
~BR
Jatin Katyal
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~Jatin
