Installing Windows 7 on EFI vs. MBR partitioned SSD

O

Objekt

Limp Gawd
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Apr 6, 2012
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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.
 
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.

Perhaps one of the biggest pitfalls of MBR-based disks is their potential for corruption of the partition table, a region on the disk that maps sectors to logical block numbers. MBR disks only have 1 partition table to keep track of all the blocks in the partition. If the table becomes corrupt, the entire disk must be recovered from backup. Windows GPT-based disks have multiple, redundant partition tables so that if one is detected as being corrupt, it can self-heal itself from a redundant copy of the table.
Click to expand...

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.
 
That's correct, I was using a Home Premium w/SP1 disc. I guess that's why I got GPT silently?
 
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)
 
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.
 
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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.
 
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Wiped my system and reinstalled on my SSD and storage HDD as GPT. So far so good.
 
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