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What does "fast startup" actually do?

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Software Windows 10
Hi everyone,

Knowing that fast startup is now enabled by default in Windows 10, I just wanted to know the details of what it actually entails to have fast startup turned on?
I googled it, watched some YT videos, no one seems to know exactly what state the system is in when you turn it off when FS is enabled. Is the RAM still powered on? how much of the CPU is actually being used?
I would guess if it's a laptop, it wouldn't be a good idea to leave FS enabled would it? you don't want to trade some battery life for 5 seconds of faster bootup time.

If you have a source detailing what FS does, I'd love to have a look.
Cheers.
 
Solution
If you have a source detailing what FS does, I'd love to have a look.

The easiest answer is that Fast Startup changes how Windows shuts down. Instead of actually shutting down, Windows instead logs the user/s off and then hibernates the OS. This makes it so when you power the computer back on, Windows doesn't go through a full boot sequence, it just resumes from the hibernated state sitting at the login screen.

It actually helps out a lot if the OS is installed on an HDD, but in the world today of cheap ass SSDs, it makes no sense to use Fast Statup.

I want to know what that means exactly, like is it saved in RAM and said RAM will be receiving power constantly so it can refresh and maintain data? is the CPU being used at...
 
It's the first thing I disable on any of my systems. I go a step further and also disable hibernation. It deletes the hiberfil.sys file which can grow to an enormous size and easily gets corrupted and causes a myriad of issues.
Open an elevated command prompt: type cmd, hit CTRL+SHIFT+ENTER, an elevated prompt should open. In this prompt type powercfg -hibernate OFF hit enter and reboot. You can turn it back on by replacing the OFF with ON.
 
Thanks but that doesn't really answer my question. It says "Only save the system booting information. When the user press the power button of the system, it will boot the system to the user default setting."
I want to know what that means exactly, like is it saved in RAM and said RAM will be receiving power constantly so it can refresh and maintain data? is the CPU being used at all? what parts of the system are still on and to what extent?
As far as I can see, the CPU uptime in task manager doesn't reset when shutting down with FS enabled which leads me to believe that the CPU is still powered on.
I hate how there aren't really any details on how it works exactly, I can't make an informed decision.
It's the first thing I disable on any of my systems. I go a step further and also disable hibernation. It deletes the hiberfil.sys file which can grow to an enormous size and easily gets corrupted and causes a myriad of issues.
Open an elevated command prompt: type cmd, hit CTRL+SHIFT+ENTER, an elevated prompt should open. In this prompt type powercfg -hibernate OFF hit enter and reboot. You can turn it back on by replacing the OFF with ON.
I do use sleep mode (it's somewhat the same ig) actually quite often, so I don't mind those big files being on my SSD. My problem is that at least on my laptop (on my main desktop PC it doesn't matter really), when I press shut down, I want the system to actually power off, not put into some sophisticated sleep state. I'd rather keep my battery life for as long as possible rather than shave off a few seconds on booting from cold which you do like twice a day or something.
 
it makes your PC unstable from what i can tell :laugh: mine has fast boot, & ultra fast, but the latter requires you to affix an Asrock sticker to the left side panel in order for it to work. windows has a fast startup too? i thought that was just a bios option. you learn something new every day i guess.
 
Cause issues.

That's it.
 
It doesn't load everything right off the start. Only the stuff that's needed for a successful boot is brought up (no USB or networking for example) and everything else is loaded later.
 
When I'm watching live streams from the internet the audio was always out of sync, once disabling fast boot/hibernate no more issues, don't ask me why but it was solved.
 
It doesn't load everything right off the start. Only the stuff that's needed for a successful boot is brought up (no USB or networking for example) and everything else is loaded later.
This, it doesn't cause issues except maybe makes it a pita to get to bios from a reboot.
 
Is hybernation that bad?

It's not even enabled on my laptop at first but i enabled it as it's quite usefull. Sleep still uses power & hibernate does not, but apparently its a bad thing?
 
Is hybernation that bad?

It's not even enabled on my laptop at first but i enabled it as it's quite usefull. Sleep still uses power & hibernate does not, but apparently its a bad thing?
It's not bad per se, if you have a use for it then it's fine. My problem is when I press shut down the thing doesn't actually shut down.
 
If you have a source detailing what FS does, I'd love to have a look.

The easiest answer is that Fast Startup changes how Windows shuts down. Instead of actually shutting down, Windows instead logs the user/s off and then hibernates the OS. This makes it so when you power the computer back on, Windows doesn't go through a full boot sequence, it just resumes from the hibernated state sitting at the login screen.

It actually helps out a lot if the OS is installed on an HDD, but in the world today of cheap ass SSDs, it makes no sense to use Fast Statup.

I want to know what that means exactly, like is it saved in RAM and said RAM will be receiving power constantly so it can refresh and maintain data? is the CPU being used at all? what parts of the system are still on and to what extent?

Everything is powered off, just like a normal shutdown. However, before Windows powers down the hardware, it saves the RAM contents to hiberfil.sys. The next time the computer powers on, the Windows boot process looks at the hiberfil.sys file and loads its contents back into RAM. Restoring things to the way they were instead of going through the entire boot sequence.

As far as I can see, the CPU uptime in task manager doesn't reset when shutting down with FS enabled which leads me to believe that the CPU is still powered on.
I hate how there aren't really any details on how it works exactly, I can't make an informed decision.

The CPU uptime counter keeps going up because it just uses the last boot time and current time to calculate CPU uptime. You can put a computer in hibernation, completely unplug it from power for a month, boot it back up, and the CPU uptime will have increased by 1 month even though there is no chance the CPU was still active.
It doesn't load everything right off the start. Only the stuff that's needed for a successful boot is brought up (no USB or networking for example) and everything else is loaded later.
This, it doesn't cause issues except maybe makes it a pita to get to bios from a reboot.
You are both talking about Fast Boot in the BIOS, this is not what the OP is asking.

It's not bad per se, if you have a use for it then it's fine. My problem is when I press shut down the thing doesn't actually shut down.

That depends on what you consider actually shut down. The OS goes into hibernation, but the hardware is fully powered off just like if you shut down Windows with Fast Startup disabled.

My problem with it is that a lot of the problems that are solved by turning it off and back on, don't get fixed with Fast Startup turned on, because the OS isn't actually restarting when you select shutdown. You have to specifically select restart for the OS to fully restart.
 
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Solution
I do use sleep mode (it's somewhat the same ig) actually quite often, so I don't mind those big files being on my SSD. My problem is that at least on my laptop (on my main desktop PC it doesn't matter really), when I press shut down, I want the system to actually power off, not put into some sophisticated sleep state. I'd rather keep my battery life for as long as possible rather than shave off a few seconds on booting from cold which you do like twice a day or something.
For the future, if it ever gets corrupted, turn it off, reboot, turn it back on, and reboot. That will delete and reset the hiberfil.sys and remove corruption.
 
The easiest answer is that Fast Startup changes how Windows shuts down. Instead of actually shutting down, Windows instead logs the user/s off and then hibernates the OS. This makes it so when you power the computer back on, Windows doesn't go through a full boot sequence, it just resumes from the hibernated state sitting at the login screen.

It actually helps out a lot if the OS is installed on an HDD, but in the world today of cheap ass SSDs, it makes no sense to use Fast Statup.



Everything is powered off, just like a normal shutdown. However, before Windows powers down the hardware, it saves the RAM contents to hiberfil.sys. The next time the computer powers on, the Windows boot process looks at the hiberfil.sys file and loads its contents back into RAM. Restoring things to the way they were instead of going through the entire boot sequence.



The CPU uptime counter keeps going up because it just uses the last boot time and current time to calculate CPU uptime. You can put a computer in hibernation, completely unplug it from power for a month, boot it back up, and the CPU uptime will have increased by 1 month even though there is no chance the CPU was still active.


You are both talking about Fast Boot in the BIOS, this is not what the OP is asking.



That depends on what you consider actually shut down. The OS goes into hibernation, but the hardware is fully powered off just like if you shut down Windows with Fast Startup disabled.

My problem with it is that a lot of the problems that are solved by turning it off and back on, don't get fixed with Fast Startup turned on, because the OS isn't actually restarting when you select shutdown. You have to specifically select restart for the OS to fully restart.
CPU uptime is usually like 2 or 3 days (with FS enabled in windows) even though I rarely use my laptop nowadays (mainly on my desktop PC). That's in conflict with the claim that the hardware is fully shut down? how does it keep count with no CPU? or does it just increment the timer with the difference in hours from last "shutdown" whenever it's turned back on?
 
It's the first thing I disable on any of my systems. I go a step further and also disable hibernation. It deletes the hiberfil.sys file which can grow to an enormous size and easily gets corrupted and causes a myriad of issues.
Open an elevated command prompt: type cmd, hit CTRL+SHIFT+ENTER, an elevated prompt should open. In this prompt type powercfg -hibernate OFF hit enter and reboot. You can turn it back on by replacing the OFF with ON.
Hibernate is complete backup of memory saved to the drive so it can completely turn off. Since its a ram backup the max size it gets is what ever current amount of memory system has installed like if you have 16gb of memory then it will be 16gb
 
CPU uptime is usually like 2 or 3 days (with FS enabled in windows) even though I rarely use my laptop nowadays (mainly on my desktop PC). That's in conflict with the claim that the hardware is fully shut down? how does it keep count with no CPU? or does it just increment the timer with the difference in hours from last "shutdown" whenever it's turned back on?

I explained that in my post. CPU Uptime is just the difference between the last boot time, which doesn't change when going into hibernation, and the current system time. It isn't an actual counter that keeps counting up. As I said, it will continue to go up even if the system has been completely unplugged from power for months.
 
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