Acceptable CPU idle % for installation

Testing a very CPU hungry app on both an iMac and a Mac Mini.
iMac > 70% CPU idle time and 20% User
Mini > 20-25% with roughly 60% total User

This latter amount seems quite high for a machine that is always ON.

As long as the mini can handle a sustained 60% utilization without damaging itself due to heat, then there should not be anything to worry about.

I would run some tests to see how high the CPU temperature gets while running your app with the mini installed in the same or similar situation as it will be for the installation.

Next, compare this to the recommended temperature ranges for your specific CPU, which you’ll likely be able to find on intel’s ARK. If you find that you’re running too hot, then can try adding some auxiliary cooling around the installation area to get temperatures down into the manufacturers recommended operating range.