USB HDD spin down and up when rebooting

[Kosake]

Hi Guys,

when i reboot my PC the USB 3.0 HDD spins down and immediately up and Windows starts.

Is there a UEDI adjustment which can prevent the spin down?

Board: Asrock Z68 Pro 3

Big thanks!!

[Kosake]

Re: USB HDD spin down and up when rebooting

no ideas?

[parsec]

Re: USB HDD spin down and up when rebooting

Your USB drive's behavior sounds normal to me, and may have multiple causes. The USB drive is reacting to one or more things happening which cannot be controlled by the user or the BIOS/UEFI. Not knowing the exact model of your USB drive makes it harder to answer your question.

When the PC is restarted all the software (Windows, etc) is terminated and the hardware is initialized/started up again, meaning it is reset. The USB drive loses its connection to Windows, and its connection to the USB interface. The drive senses that and apparently goes into a low power usage sleep state and spins down, which makes sense.

Shortly after the above, the USB interface is started up, and the POST process finds the drive on the USB port. The USB drive reacts to its connection to a USB interface being made again, and spins up. The POST process will connect the drive to the USB interface as it does with any drive connected to the PC that has power, and pass that connection along to Windows so the drive will be listed and available when it boots. So a restart is very similar to a cold start/boot for the USB drive.

If that USB drive is getting power from the PC over the USB cable, there may also be a momentary loss of power to the USB ports caused by the restart. That of course will cause the USB drive to spin down and require its own restart.

So many things going on that can cause the USB drive to act as it does on a system restart, and I may have missed one or two.