Tor 브라우저와 다른 브라우저를 동시에 실행해도 Tor의 성능이나 개인 정보 보호에는 영향을 미치지 않습니다.

However, be aware that when using Tor and another browser at the same time, your Tor activity could be linked to your non-Tor (real) IP from the other browser, simply by moving your mouse from one browser into the other.

Or you may simply forget and accidentally use that non-private browser to do something that you intended to do in Tor Browser instead.