External Hard Drives Ignoring "Turn off Hard Disk After" Setting – Mixed Results on Win 10/11

I have two laptops (Windows 10) and a mini-PC (Windows 11) with external USB hard drives connected. The "Turn off hard disk after" setting is set to 10 minutes on all devices, but the drives turn off at different times on each machine. One shuts off around 2 minutes, another at 3, another at 6, and during RDP sessions, it’s even shorter (one of them even turns off HDDs after 5 seconds which was driving me crazy). I'm using the same Hard Drives to test individually on each PC.

It seems like the timer is only respected if it's below an unknown max limit that varies per PC (if I set to it to 1 min it will turn off after 1 min). Anyone knows how to resolve this issue?

Win 11 23H2
Win 10 22H2
Win 10 21H2

Serious question...what is the purpose, what is gained and/or prevented by turing off external hard drives? I have a Win10 desktop and a Win11 laptop, both have external USB hard drives attached. The laptop is new but both external drives have been in place literally for years. What am I missing??

I found a solution for 2.5" HDDs but not for 3.5" as the "USB Mass Storage Device" entry doesn't show up in device manager for 3.5" HDDs.
Disabling 'Allow the computer to turn off this device to save power' will prevent HDD to go into sleep.
If anyone knows why "USB Mass Storage Device" doesn't appear for 3.5" HDDs connected through USB please let me know.

It seems it's appearing under "Storage Controllers" as "USB Attached SCSI (UAS) Mass Storage Device" but there is no "Power Management" tab.

Anyone found or knows a solution please?

fa1rid said:

Anyone found or knows a solution please?

Click to expand...

Check out 3 just below in your Device list, the Intel USB host controller can be turned off/on.

OAT said:

Check out 3 just below in your Device list, the Intel USB host controller can be turned off/on.

Click to expand...

I tried that before you even mention it.