I'm sorry, I didn't measure so I can't give you an exact answer.
However, as I said previously do all the other initiatives first to get it back to working quickly.
If you find that it still is slow after all that work, then consider purchasing a C7 to be used just for "device control".
Also, there are other approaches to dividing up the load. One individual has a Hub for each floor in his house. Others (such as myself), use one hub for devices and one hub for control. One individual has one hub for zwave and one for zigbee. In other words, your mileage may vary - before going down this route, plan it out carefully.
I would like to also recommend an excellent response that I read some time ago. It posits that the reason for slowdowns is the lack of memory, and it gives a few practical suggestions on how to increase that memory:
[RELEASE] Hub Watchdog - Simple way to monitor if your hub is slowing down or not
Specifically this:
