Raspberry IP cameras

I have three ip cameras connected to raspberry pi3 B, but I think that it’s too much for the raspberry hardware. The live feed it’s laggy and after 3 seconds it stop, I use it also for facial recognition with microsoft face component.
I was thinking to buy another raspi (model B+) and move the cameras connection to it, but I have no idea on how to connect the first raspi with hass to the new one with the cameras.

Anyone has a solution for this?