Do VMs create a large power draw on top of unraid and dockers? My UPS is showing a 110 to 140 Watt Load. I'm replacing an older core i3 gaming rig with a VM, am I going to actually save any electrical use doing this? I'm thinking about replacing my other dedicated PC which is a HTPC with another VM

 

My 2 dedicated PCs spent most of the time during work hours and after 10:30 pm sleeping, I have left the one VM I have created on 24/7 but I feel like I'm probably still saving power, does anyone know if this is true?

 

Finally If I pass a GPU and USB controller through to my htpc  VM is it possible to sleep it and wake it via usb, or again is it not worth the power savings since it's not a real PC?

In my experiences with this (kill-a-watt attached) my Win8.1 VM with no passthrough takes little to no additional power draw.

 

If you pass through devices you will have the draw for those, however most USB devices will be minimal at best.

Your larger concern would be a GPU that does not have a low idle power state (edit: this used to be much more of an issue than cards made in the last 5 years), which could increase consumption by as much as 50% total at idle (I idle when "the moons align" at ~60w) as some older cards will absolutely idle at 30w or more.

 

Newer GPU's, and use cases that are used specifically for media serving purposes (so gaming isn't their best attribute) will idle at insignificant amounts, ~3 watts or so, with a full power usage <30 watts (dependent upon the card). I believe that setting the monitor to never sleep in Windows (so GPU continues to output) will consume a little more power usage, however still (in above use case) not significant, but I enable this to a set time anyhow.

 

If you are okay with your server being on 24/7 (I am in this camp), then your VM's will not make much impact to overall power draw as long as they are not continuously processing any heavy workload (example, if you "fold@home" in a Windows VM, your CPU will not idle very often, increasing power draw).

 

The 750Ti that you speak of in another thread shows an idle consumption of 6w here: http://www.tomshardware.com/reviews/geforce-gtx-750-ti-review,3750-21.html

which is pretty insignificant.

 

Hope that helps.

Thanks for the info, I do run my server 24/7, and since it's not going to have much of an impact I'm just going to run these 2 VMs all the time as well.