Different boot times for dual Windows 11 installations on same PC


BadAnalysis

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Windows 10/11
Hi folks. I've successfully installed and isolated two installations of Windows 11 on my PC. One for work (Pro) and one for games (Home). I've moved the EFI partition to its own dedicated drive and removed the original and things work flawlessly. I've disabled Fast Startup, and disabled the drive for the alternate OS in Device Manager and they appear to be completely isolated from one another. The strange thing is that when selecting which OS to start on the bootloader, the original (work) installation starts up very quickly whereas the second (games) installation restarts the PC and takes much longer to load.

I can't understand why because the EFI/bootloader partition is completely isolated on its own drive and both OS installations are on fast M.2 NVMe SSDs so I can't account for the difference. I've double-checked that Fast Startup is disabled on each, there is no hibernate file and neither are encrypted or have any substantial difference in configuration.

Could anybody provide any insight into this? I'd appreciate it.

Thanks.
 
Windows Build/Version
Windows 11 Pro/Home

My Computer

System One

  • OS
    Windows 10/11
    Computer type
    PC/Desktop
    Manufacturer/Model
    Self-assembled
    Other Info
    Changes every few days :)

CornishRattler

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Mine is the same, the last Os installed will be the default OS unless you have specified a different OS after installation and this will preload ready for deployment, that's why when you select the default it loads very quickly, when you select another OS it goes through the initial boot process all over again so takes a little longer. Hope that makes sense, I'm sure someone will be along with over complicated technical jargon to explain the same thing but in essence that's how mine behaves.

You
 

My Computer

System One

  • OS
    Windows 11 Pro Beta, 11 Dev, W10 VHDX Triple Boot
    Computer type
    Laptop
    Manufacturer/Model
    Dell Alienware M15 Ryzen Edition R6
    CPU
    AMD Ryzen™ 9 5900HX
    Memory
    32GB
    Graphics Card(s)
    NVIDIA® GeForce RTX™ 3070 8GB GDDR6
    Hard Drives
    1 x Samsung 980 Pro 1TB
    1 x Samsung 970 Evo Plus 1TB

BadAnalysis

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Windows 10/11
Thank you very much for your answer. That actually strikes me as a bizarre decision given that I always assumed that the bootloader would be an independent component of the boot process and that having it interact with the OS (or multiple OSs) would violate the ideas of compartmentalisation and least privilege. I can understand some interaction such as facilitating a chain of trust but preloading the OS takes me by surprise.
 

My Computer

System One

  • OS
    Windows 10/11
    Computer type
    PC/Desktop
    Manufacturer/Model
    Self-assembled
    Other Info
    Changes every few days :)

cereberus

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Mine is the same, the last Os installed will be the default OS unless you have specified a different OS after installation and this will preload ready for deployment, that's why when you select the default it loads very quickly, when you select another OS it goes through the initial boot using msconfigprocess all over again so takes a little longer. Hope that makes sense, I'm sure someone will be along with over complicated technical jargon to explain the same thing but in essence that's how mine behaves.

You
Yeah, I get similar.

I just did a test by changing the default OS using MSConfig to one I wanted to boot into, and it booted much more quickly.

I never really thought about this, but now you have pointed this out, I may produce a batch file using

bcdedit /default {88240e47-5ebf-11e7-98a8-b123c369fcff}

where figures in {} are the guid for os I want to boot to.

I would a series of these for each guid, and a simple menu to select whichever I wanted.

Then I would have a shutdown and restart command.

Small project for weekend.
 

My Computer

System One

  • OS
    Windows 10 Pro + others in VHDs
    Computer type
    Laptop
    Manufacturer/Model
    ASUS Vivobook 14
    CPU
    I7
    Motherboard
    Yep, Laptop has one.
    Memory
    16 GB
    Graphics Card(s)
    Integrated Intel Iris XE
    Sound Card
    Realtek built in
    Monitor(s) Displays
    N/A
    Screen Resolution
    1920x1080
    Hard Drives
    1 TB Optane NVME SSD, 1 TB NVME SSD
    PSU
    Yep, got one
    Case
    Yep, got one
    Cooling
    Stella Artois
    Keyboard
    Built in
    Mouse
    Bluetooth , wired
    Internet Speed
    72 Mb/s :-(
    Browser
    Edge mostly
    Antivirus
    Defender
    Other Info
    TPM 2.0

CornishRattler

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Windows 11 Pro Beta, 11 Dev, W10 VHDX Triple Boot
Yeah, I get similar.

I just did a test by changing the default OS using MSConfig to one I wanted to boot into, and it booted much more quickly.

I never really thought about this, but now you have pointed this out, I may produce a batch file using

bcdedit /default {88240e47-5ebf-11e7-98a8-b123c369fcff}

where figures in {} are the guid for os I want to boot to.

I would a series of these for each guid, and a simple menu to select whichever I wanted.

Then I would have a shutdown and restart command.

Small project for weekend.
Whichever one you have as the default OS will boot quickly, the other(s) will take longer after selecting at the boot screen. We are only talking seconds here mind
I have W11 Beta as my default. W11 Dev and W10 take longer to boot, if I change the default to W11 Dev then W11 Beta takes a little longer etc, etc
 

My Computer

System One

  • OS
    Windows 11 Pro Beta, 11 Dev, W10 VHDX Triple Boot
    Computer type
    Laptop
    Manufacturer/Model
    Dell Alienware M15 Ryzen Edition R6
    CPU
    AMD Ryzen™ 9 5900HX
    Memory
    32GB
    Graphics Card(s)
    NVIDIA® GeForce RTX™ 3070 8GB GDDR6
    Hard Drives
    1 x Samsung 980 Pro 1TB
    1 x Samsung 970 Evo Plus 1TB

cereberus

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5:48 AM
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Windows 10 Pro + others in VHDs
Whichever one you have as the default OS will boot quickly, the other(s) will take longer after selecting at the boot screen. We are only talking seconds here mind
I have W11 Beta as my default. W11 Dev and W10 take longer to boot, if I change the default to W11 Dev then W11 Beta takes a little longer etc, etc
You say seconds, but it is 12 seconds difference on my pc, and that is with fast nvmes - it is restarting twice in effect that slows things down. Batch file will take 1 second.
 

My Computer

System One

  • OS
    Windows 10 Pro + others in VHDs
    Computer type
    Laptop
    Manufacturer/Model
    ASUS Vivobook 14
    CPU
    I7
    Motherboard
    Yep, Laptop has one.
    Memory
    16 GB
    Graphics Card(s)
    Integrated Intel Iris XE
    Sound Card
    Realtek built in
    Monitor(s) Displays
    N/A
    Screen Resolution
    1920x1080
    Hard Drives
    1 TB Optane NVME SSD, 1 TB NVME SSD
    PSU
    Yep, got one
    Case
    Yep, got one
    Cooling
    Stella Artois
    Keyboard
    Built in
    Mouse
    Bluetooth , wired
    Internet Speed
    72 Mb/s :-(
    Browser
    Edge mostly
    Antivirus
    Defender
    Other Info
    TPM 2.0

CornishRattler

Well-known member
Pro User
VIP
Local time
5:48 AM
Posts
1,822
Location
Cornwall UK
OS
Windows 11 Pro Beta, 11 Dev, W10 VHDX Triple Boot
You say seconds, but it is 12 seconds difference on my pc, and that is with fast nvmes - it is restarting twice in effect that slows things down. Batch file will take 1 second.
So in essence you're changing and pre-selecting the default OS before you shutdown, I think it's about 10 seconds on mine but 10 or 12 it's "seconds" all the same. Just thinking of what else that's productive (apart from switching the kettle on) I could be doing in those fleeting moments and I'm not coming up with much tbh
 

My Computer

System One

  • OS
    Windows 11 Pro Beta, 11 Dev, W10 VHDX Triple Boot
    Computer type
    Laptop
    Manufacturer/Model
    Dell Alienware M15 Ryzen Edition R6
    CPU
    AMD Ryzen™ 9 5900HX
    Memory
    32GB
    Graphics Card(s)
    NVIDIA® GeForce RTX™ 3070 8GB GDDR6
    Hard Drives
    1 x Samsung 980 Pro 1TB
    1 x Samsung 970 Evo Plus 1TB

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