Q: I need to monitor a large number of desktop operating systems with System Center Operations Manager. Do the typical scalability numbers for Operations Manager still apply?
A: The Microsoft TechNet article "System Requirements: System Center 2012 - Operations Manager" covers the maximums for System Center Operations Manager 2012, in the Monitored Item Capacity section. Although these maximums aren't hard limits, they're the numbers Microsoft has tested and that you should stick to for ensured support.
The workload for monitoring desktops is typically far less than for a server operating system. Therefore, if you want to push the support limits you could probably monitor more desktops than the recommended server workload limit. However, you'd need to test this thoroughly.
For desktops, you should adhere to the following limits:
- 3,000 machines per management server
- 15,000 machines per management group
You can use the System Center 2012 Operations Manager sizing tool to determine the exact hardware requirements.