Why is a cold boot much faster than a restart with USB plugged in?

More or less thoroughly explained here.
How to Make Windows Ignore an External HDD and Boot Faster

But DO NOT fiddle around with this without being absolutely sure about what you are doing!

My thought is that a restart/reboot already knows about the drives and is checking the contents while a cold start is just checking what drives or other devices are available and won't check contents until called for after the OS has loaded, makes the cold start faster.

Charlie210 said:

I am running Windows version 22H2 with all current updates. My bios settings have an internal M.2 PCIe drive selected as 1st boot drive. I have only one external USB drive attached to a M.2 USB 3.2 Gen 2x2 Vantek PCIe Host card using a USB 3.2 Gen 2 M.2 NVME enclosure. with a 2T SSD.

My cold boot time with and without USB plugged in is 13 seconds. My restart time with USB plugged in is 60 seconds while only 20 seconds with USB not plugged in. Waking from sleep mode with and without USB is the same at 19 seconds.

My question is why is a cold boot significantly faster that a restart? It's no big deal but just curiosity asking the question. I would think the restart time would be shorter than a cold boot.

Several reasons:

A restart has to close down the existing instance and then restart.

A cold start only starts a new instance.

To make a fair comparison, you have to add the time to shutdown to the restart time for a cold boot, so you can compare it with the restart case.

Also a warm start has to manage the temporary files like pagefile, hiberfil etc. These are largely irrelevant in a cold restart.

However, if you have fast start enabled, the pc basically uses a sort of cutdown hibernation to speed startup and that only works on cold boot not restarts, so pc is quicker at starting. The trade off is you have to write the hibernation file as part of the shutdown.

Fast startup can cause unexpected issues, particularly on dual boot pcs.
With modern ssd/nvme drives, I prefer to disable fast start up, then just shutdown and do a cold reboot as it is always faster.

My cold boot time with and without USB plugged in is 13 seconds. My restart time with USB plugged in is 60 seconds while only 20 seconds with USB not plugged in. Waking from sleep mode with and without USB is the same at 19 seconds.

Why does restart take 40s longer with a USB drive plugged in, when a cold boot is unaffected by its presence?

That's a question none of the above tries to answer.

I don't know, but if the time you're quoting is the time to lock screen, 13s is quite long... this 8-9 year-old laptop with a SSD boots to lock screen in about 9s.