My advice - Turn it off 
Long ago, when vacuum tubes ruled the electronic world this was a major issue. A lot of gear, as well as many consumer HIFI and televisions later incorporated a standby switch which would just keep the heating elements under a slightly reduced current.
With modern solid state and microdevices this is hardly an issue any more and in fact in many cases the reverse is true. In the old world heat was integral as much of the the electronics relied on principles of thermionic emission (some high end and calibrated equipment even required the tubes to be “aged” = kept under current for a time like a vintage wine) - in the modern world, heat is generally the enemy and is a primary factor responsible for shortening the life of a given component. As the devices become smaller, the current required to operate them becomes smaller resulting in much less heat being generated overall. The greatest power hogs in a modern computer are usually the fans and devices involved in cooling the local environment down!
Consider also mechanical disk drives which many still have in use - and with the fact that many have defeated the power saving features of their DAW, these will never rest - increasing their likelihood of failure.
Lastly, think that many computers are connected to the internet, and if the computer sits there idle for long periods, this could give a hacker ample time to hack into your system! 