according to reference it should be 50
http://www.cisco.com/en/US/prod/collateral/vpndevc/ps5739/ps6498/qa_c67-459942.html
Q. What options are available to evaluate Cisco Security Manager?
A. Anyone with a valid Cisco.com account can download Cisco Security Manager and use the software for up to 90 days in evaluation mode. Go to http://www.cisco.com/go/csmanager and access the "Download Software" link. One limitation of the download is that it does not include CiscoWorks Resource Manager Essentials (RME).
For customers that wish to also evaluate CiscoWorks RME or that prefer a media format rather than a large download, an evaluation DVD can be ordered from Cisco Marketplace. Visit http://www.cisco.com/pcgi-bin/marketplace/welcome.pl; navigate to the Collateral and Subscriptions Store and search for part number EVAL-CSMGR-3.2.
There is no separate evaluation license. The product operates automatically in evaluation mode in the absence of an installed permanent license file. Evaluation mode is equivalent to Cisco Security Manager Professional Edition with a 50-device limit, with the exception that the evaluation mode expires 90 days after installation.
