Switching to an eMachines EL1300G computer drastically cut the running power consumption of my MythTV setup, to an average of 45 watts when idle. (The old computer used 141 watts when idle.)
This makes it practical to leave the computer on 24/7. I had set my old computer to shut itself down when not recording, but this required a 2 minute boot-time wait anytime we wanted to watch TV. (When it was not already awake recording a show). Even when the old computer was off, the constant current draw from the other devices (UPS/HDHomeRun/Amplifier) was 17 watts.
The new computer takes 25 watts (when idle, up to 35 when playing video) for a total of 45 watts constant draw including the standby draw of the TV/DVD when recording shows or idle. This is more than the 17 watt draw when the old computer was off, but the added benefits is worth the extra 20 kWh a month ($2.20) in electricity.
The two primary benefits are:
- Being able to turn on the TV with a remote control and go immediately.
- Being able to use the mythTV computer as a home file and print server, that is available 24/7.
And, if you consider that the old computer was not shut down all the time, but was running 2-5 hours a day while recording shows and being used to watch TV (drawing 150 or more watts, compared to the 35 watts max the current computer uses), a savings of (3 * (150-35) * 30) = 10.3 kWh or more a month, my actual electricity usage is only increasing by $1.20 or less a month for the benefits of being able to access the home file/print server and TV immediately.