Installing Windows 7 on EFI vs. MBR partitioned SSD

Discussion in 'Operating Systems' started by Objekt, May 12, 2012.

  1. Objekt

    Objekt Limp Gawd

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    I was up all last night putting together my latest build, which has an Intel 520 series SSD as its one and only drive. The motherboard is a Gigabyte GA-Z77-DS3H (a UEFI-capable board) with a Core i5-3570K CPU. I left most of the BIOS settings at defaults for my Windows 7 64-bit install, except for putting the SATA controller in AHCI mode.

    So I ended up with the SSD being formatted GPT. I don't remember Windows setup asking me whether I wanted to format the disk as GPT or MBR. Either it happened automagically, or I was tired and missed it.

    At 120 GB, the SSD is not big enough to require GPT, so is there any particular advantage to sticking with a GPT-'ed SSD? As far as I know, the main selling points of GPT are:
    -many more partitions
    -access to very large (>2 TB) disks.
     
  2. CleanSlate

    CleanSlate [H]ardness Supreme

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    I'm not sure how it got converted into a GPT partition considering I don't remember this being a default in windows 7- maybe you're using a windows 7 sp1 disk which I've never used and only assume exists.

    As this article is quoted above: http://www.petri.co.il/gpt-vs-mbr-based-disks.htm


    There is a big advantage to using GPT partitions in redundant boot records so that if corruption occurs in the boot record it can be easily fixed with the GPT architecture. Not so with the regular MBR. I would leave it as is.
     
  3. Objekt

    Objekt Limp Gawd

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    That's correct, I was using a Home Premium w/SP1 disc. I guess that's why I got GPT silently?
     
  4. CleanSlate

    CleanSlate [H]ardness Supreme

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    It's a possibility that sp1 installs default to GPT but that's just a guess.
     
  5. bigdogchris

    bigdogchris [H]ard as it Gets

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    delete
     
    Last edited: May 13, 2012
  6. SuperSubZero

    SuperSubZero 2[H]4U

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    Some UEFI boards default to MBR and they need to be explicitly booted in UEFI mode (I've seen some Dell laptops do this)

    Some UEFI boards default to UEFI and they need to be explicitly booted in MBR mode (I've seen some Lenovo laptops do this)
     
  7. bigdogchris

    bigdogchris [H]ard as it Gets

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    OP I think what happened is that when you booted to your DISC or USB drive to install the OS that you selected the UEFI: variant, which boots to EFI installation mode, which is used in installing to GPT disk.

    For example, when you selected your boot menu, you have the following choices:

    CD-ROM
    UEFI:CD-ROM
    USB
    Hard Disk

    etc.

    Read up on that here.
     
    Last edited: May 13, 2012
  8. bigdogchris

    bigdogchris [H]ard as it Gets

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    To share my results in another thread I'm working with, I found that if you use the DVD and select the UEFI shell option when booting to DVD, that it will automatically convert the disk to GPT and install the OS. It is completely seamless to the user. No Shift+F10 is required.

    For those using USB drive, you must go through a process of changing some files in the EFI boot directory. The DVD does not require the changes for some reason.

    When you installed the OS, did you put the UEFI:DVD as the first boot device? The board may of also defaulted to the UEFI shell option.
     
    Last edited: May 16, 2012
  9. SpoonMaN-EQ

    SpoonMaN-EQ Limp Gawd

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    well its obvious that UEFI was used, Windows cannot boot from GPT in bios mode.
     
  10. bigdogchris

    bigdogchris [H]ard as it Gets

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    Wiped my system and reinstalled on my SSD and storage HDD as GPT. So far so good.