After running the powercfg /ENERGY command, I get the following Efficiency Diagnostics Report with 6 errors:
USB Suspend:USB Device not Entering Selective Suspend
This device did not enter the USB Selective Suspend state. Processor power management may be prevented when this USB device is not in the Selective Suspend state. Note that this issue will not prevent the system from sleeping.
Device Name Generic USB Hub Host
Controller ID PCI\VEN_8086&DEV_1C2D Host
Controller Location PCI bus 0, device 26, function 0
Device ID USB\VID_8087&PID_0024
Port Path 1
Here is an image of the Power Efficiency Diagnostics Report:
And here the Power Management Settings for Generic USB Hub in the Device Manager:
What / where might the problem be?
Best Answer
First question to answer, is it the hub, or something downstream? It appears to me this is an external hub, so you can unplug everything from it and see if you get the same results. (Use Device Manager View/Devices by connection for more information.)
If it is the hub itself, I see the options 1) don' t use it (at least unplug it before sleep), 2) get the updated driver which makes it work properly, or 3) deal with the fact that it will use more power than necessary. (RE 3, You probably don't want things hanging off your system on USB if you want no battery loss anyway, because even Suspend requires ~300uA per device.)
In general, a lot of "low power" is more marketing than substance, so check the real effect on your battery before you get worried. The fact is, your system uses a lot of power when you are using it, so when you aren't, it can still use a fair amount without making much difference (unless you want to leave it sleeping on your desk for a month, in which case, maybe turn it off?).