How long can an iMac stay on? I have an older iMac from 2011.

The internal hard drive has failed so it’s running off an external.

A graphics glitch occurs when it sleeps or the screensaver comes on.

I just need to work on it for the summer.

Can I just leave it on 24/7 until it dies?

It seems intuitively more taxing to turn it off and on every day.

The fan kicks on sometimes.  I’ve never had it on long enough to know if the fan eventually stops once it’s done freaking out about a task.