The Enterprise Manager Virtual Edition maximum how many BIG-IP devices can be managed?

Answer its it depends. :)

It will depend on how much CPU and RAM you have on the host. Another thing to watch for is stats polling, the more frequent you do that will have impact on performance.

I have seen EM VEs with 100 managed devices with no issue, just depends on what you want EM to do for those devices and how frequent you pool the stats from the other devices from EM.

Make sense?