Why is restart on Windows 10 way slower than cold boot?

So I've been tweaking things on my system, both hardware and software, and I now have pretty much instant boot on cold startup.

Very nice.

But restart is much slower, and takes a good 4-10 seconds to get to the login/lock screen.

Is this deliberate, and if not, what could be causing it in my case?

Thanks.

By default Windows 10 does not shudown completely as older Windows versions did. By shutting it down Windows writes the state of the kernel and drivers into the hiberfil.sys file on c. When you boot your computer Windows simply loads that file into ram, doing so let's Windows boot much faster than it would be possible otherwise. This procedure is also known a Fast Startup.

A restart on the other hand completely shuts down Windows 10 and everything has to be loaded from scratch, that's why it usually takes longer than a cold boot.

You can read more about Fast Startup as well as how to enable/ disable it here and here. It's also possible to force a full shutdown by entering this command either in cmd or in a batch file: %windir%\System32\Shutdown.exe /s /t 0.

Fast Startup is enabled in Windows 10 by default. If you don't want it you have to deliberately disable it.

Thank you everyone, I knew about fast startup, I thought hiberfil was only related to sleep mode though?

I did recently re-enable hiberfil because the version of sleep I had, while instant (hiberfil off), may have been causing some issues on wake with some lockups etc.

The thing I didn't realise, and I did learn shortly after posting this, is that while reboot is still a complete erasure and start again, the newer versions of Windows' fast startup isn't strictly hardware, which I thought it was, but is restoration of cache written, as you say, to hiberfil.

So, there's no way to make reboot as quick as fast startup?

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altae said:

Fast Startup is enabled in Windows 10 by default. If you don't want it you have to deliberately disable it.

I will say a few misunderstandings may have occured here - I like the fast startup, I just want that same speed in reboot too!

Reboot definitely needs to work like this. Why do you reboot? You reboot either because the system has become unstable or because some change you did needs a reboot. If Windows only wrote the current state of the system to the hiberfil.sys and reloaded it afterwards this would be counter productive, in those cases you absolutely want a fresh start.

I guess I've not made myself overly clear, for which I apologise.

I'm not complaining about what reboot does, nor trying to make cold startup faster, I am wondering if there's a way to make it do reboot close to as quick as cold boot.

After all, I'm on an SSD which is reading at 500M a sec - i get what reboot does (I knew that major in computer engineering would come in handy) but with the tech I have (9600K @ 5Ghz, 16GB 3800MHz DDR4, NVME SSD M2, SATA M2, and SATA SSD 2.5 x 2), fast startup seems about right in terms of speed while restart seems a bit slow.

But... that's just the way it is, you guys say?