If you don't know what to do with your CPU's, give CryptoTab a try (referral link).
It acts like a Chrome based browser, but ignore that part. It has functioning Monero miner built in that runs fine and converts to BTC. As long as the browser window is not minimized, it will run.
Running looks like this:
The browser does not need to be the foreground application or even be used at all outside of acting like a mining window. You can install it on as many PC's as you want and just log into your account on each to pool your hash.
I've had it running off and on a couple PC's at home for about a year, I pull a payout every moth and in total before the randomX fork, total mined and paid: 0.01250096 BTC. I recently setup a little farm in the basement with old PC's and I am averaging 10000 sats per day. Below is a daily snapshot taken at around the same time everyday, last 12 days. Here's the Link again, CryptoTab
