When capturing events happening seldom it would be good to be able to not have live view running.
Otherwise my computer grinds to a halt if I try to do anything else whilst waiting for my trigger.
Sorry to hear about the performance hit! Does clicking the "Live" button on the bottom-left of the screen during your capture help? This will make it so that the viewport will not auto-pan to the latest incoming recorded data, and may give a performance boost.
Also, feel free to send me (Tim) an email using the link below and send me your PC specs. We can look into the performance issue you are running into in more detail this way.