Performance in Plesk

If you have a lot of domains, or if a particular domain is causing connection problems for the rest of the server, it is possible to configure Plesk to limit the maximum bandwidth usage, the number of connections, or both to a particular subscription.

Good general values would be about 300 Kb/sec as an upper limit for the maximum bandwidth usage, and a 25 connection limit; this results in 12 Kb/sec per connection when the domain is at its connection limit, which should allow most web pages to download in a reasonable amount of time.

Because we did not allow subscriptions to change these items in the Permissions tab, this can be a good way to prevent a domain from hogging all the network resources on the server, so set these items accordingly.