Yeh each cpu is different, some need to add vcore really early some right at the end. Thats why its never easy to fully give direct info.
Yeh you are fine to use your computer whilst prime is running, maybe not gaming or any intensive tasks, but web browsing and the like is fine.
Yeh you are fine to use your computer whilst prime is running, maybe not gaming or any intensive tasks, but web browsing and the like is fine.