I just measured this on real hardware, which is a useful sanity check for hashprice. A 24-thread desktop mining RandomX through MoneroOcean does about 4 kH/s. Against that pool's 248 MH/s it is 1.6e-5 of pool revenue, roughly 0.00024 XMR a day at current prices, so about $0.15. The same box pulls roughly 100 W over idle, which at $0.14/kWh is about $0.34 a day in power. Mining at hobby scale is negative carry unless the hardware is already running, so the marginal wattage is near zero. For an always-on home server with idle cores it is a rounding error in your favour. For a gaming rig that otherwise sleeps it is a small loss.
I just measured this on real hardware, which is a useful sanity check for hashprice. A 24-thread desktop mining RandomX through MoneroOcean does about 4 kH/s. Against that pool's 248 MH/s it is 1.6e-5 of pool revenue, roughly 0.00024 XMR a day at current prices, so about $0.15. The same box pulls roughly 100 W over idle, which at $0.14/kWh is about $0.34 a day in power. Mining at hobby scale is negative carry unless the hardware is already running, so the marginal wattage is near zero. For an always-on home server with idle cores it is a rounding error in your favour. For a gaming rig that otherwise sleeps it is a small loss.