EFI SYSTEM Partition 99MB instead of 100MB

Discussion in 'Windows 8' started by oliverjia, Apr 5, 2014.

  1. oliverjia

    oliverjia MDL Addicted

    Mar 1, 2008
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    Hi,

    Just fresh installed Windows 8.1 with update Enterprise x64 (using a boot USB created from the ISO) on my main computer. the OS drive is 128GB SSD. One thing I noticed was that when the OS installer created the GPT partitions automatically, the EFI only has 99MB. I previously had Windows 8.1 x64 installed on the same drive and same computer, with a EFI of 100MB. So my question is, what could possibly caused this change?
    The only thing I did before the installation was I used low level format tool on the SSD (quick format to remove boot info). Any input?
     
  2. murphy78

    murphy78 MDL DISM Enthusiast

    Nov 18, 2012
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    You should be fine. The EFI system partition uses only 25-30megs of the 100 for a single install. It only makes it larger for multi-boot support.
     
  3. =)(=

    =)(= Guest

    Who cares about 1 MB :p
     
  4. oliverjia

    oliverjia MDL Addicted

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    Thanks for the info..
    I did a quick google search and it appears both Ubuntu and Linux Mint require at least 100MB EFI to install.
    If I plan to install Ubuntu 14.04 when it comes out on April 17, on a second 500GB HDD for dual boot, not sure if it will work? I mean, will the EFI partition for Ubuntu be on the 500GB HDD, or will it be using the same EFI partition on SSD?


     
  5. CorporateRAT

    CorporateRAT MDL Member

    Aug 4, 2012
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    Now that you posted it i checked, and indeed new installer for update iso creates 99 mb EFI partition. It was 100 mb before.
     
  6. Mr.X

    Mr.X MDL Guru

    Jul 14, 2013
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    Well, after CorporateRAT input I would say it's a new change implemented in this Update. Why? Don't know:D
     
  7. murphy78

    murphy78 MDL DISM Enthusiast

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    Some advanced format 4kn (I think that's right) drives require an efi of 260

    My pro install created a 100 meg partition... I have no idea why the rest of you have 99.
     
  8. oliverjia

    oliverjia MDL Addicted

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    #8 oliverjia, Apr 5, 2014
    Last edited: Apr 5, 2014
    (OP)
    Thanks for your confirmation. Are you using SSD or HDD?

    I just did a fresh install of 8.1 with update, using the same boot USB on a spare laptop computer, it created 100MB EFI (same as before when 8.1 was installed on this laptop). The laptop has a 500GB HDD but the OS partition was only about 70GB.

    Maybe the difference in size of EFI is due to SSD vs HDD?

     
  9. oliverjia

    oliverjia MDL Addicted

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    Murphy could you please let us know if your OS drive is SSD or HDD? It might related to type of OS drive?

     
  10. CorporateRAT

    CorporateRAT MDL Member

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    I use 120 gig sandforce based ssd.
     
  11. murphy78

    murphy78 MDL DISM Enthusiast

    Nov 18, 2012
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    Yes I'm using a spinning drive rotary setup.
    Well, raid 0 striped technically.
     
  12. oliverjia

    oliverjia MDL Addicted

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    Thanks guys for confirming your OS drive type.
    It appears to me there might be a correlation here between EFI size and type of OS drive.
    It would be great if more ppl please report your OS drive type (SSD vs HDD) and EFI size when you do a fresh install of Win8.1 with update ISO/USB.
    Interesting.
     
  13. kbman

    kbman MDL Novice

    Dec 24, 2012
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    windows 8.1 update 1 120gb ssd 100mb efi
     
  14. oliverjia

    oliverjia MDL Addicted

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    Thanks.
    Did you do clean install on the SSD, i.e., the SSD was unformatted before installation?

     
  15. kbman

    kbman MDL Novice

    Dec 24, 2012
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    Yes it was a clean install with unpartitioned drive.
     
  16. Ahsan

    Ahsan MDL Addicted

    Dec 3, 2009
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    HI attached is my 500gb GPT partitioned dell WDC hard disk , i have removed the OEM / Image / Winretools partitions and now the situation is as in the picture...I want to merge H and D partitions and then to merge F and C partitions using EASEUS but it is not merging and saying some errors have ocurred , can any expet have a look and suggest a way out ,

    thanks:)
     

    Attached Files:

  17. Ahsan

    Ahsan MDL Addicted

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    hello anybody here????
     
  18. ianymaty

    ianymaty MDL Member

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    Delete H and F partitions.

    Resize D and C partitions over the addiacent unallocated space.
     
  19. Ahsan

    Ahsan MDL Addicted

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    yes tried and also ran chkdsk /f on drives , EASEUS asked for reboot but a black screen came with Partion Boot Mode written on it and computer stuck , luckily windows rebooted , status is still same , EaseUS Partition Master 9.3.0 is not working i guess in this case.
     
  20. ianymaty

    ianymaty MDL Member

    Jan 31, 2010
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