SSD: Initialize as MBR or GPT?

Should I initialize my SSD as MBR or GPT?

“Hello, guys. I recently bought a new 1TB SSD to replace my old one. I'm preparing to boot up my new SSD. But then I was given the choice of choosing between MBR and GPT layouts, and I have no idea what the distinctions are, and I couldn't find a satisfactory response on the internet. Please, if at all possible, simplify. Thank you ahead of time. Also, it will be my boot drive (if that wasn't apparent) with a couple of huge open-world games on it, which should help me decide which one to play.”

A brief review of MBR & GPT

You’ll be asked to choose between MBR & GPT when you try to initialize a new disk. Some users might know a new disk, no matter HDD or SSD, should be initialized first. However, MBR and GPT, need more information to make a suitable choice for their devices. So, here, we’ll do a brief review of MBR and GPT. If you need more details, you can go to The differences between MBR and GPT.

Distinct techniques are used to manage the partitions on a disk by the two different types: MBR and GPT.

▶ MBR: Master Boot Record

It restricts a disk's maximum storage space to 2 TB. Furthermore, it only supports up to 4 primary partitions or 3 primary partitions plus one extended partition combination. To add extra partitions, make one of the primary partitions an "extended partition" and then add other logical drives within the extended partition.

▶ GPT: GUID Partition Table

The GPT is a more recent disk layout that is related to UEFI. As technology advances, more storage devices must be used in the computer industry.

GPT partition table disk supports volumes of up to 264 blocks in length, e.g., 9.44 ZB for disks with 512-byte sectors, and up to 128 primary partitions. This partition style can hold boot information at the beginning and end of a disk's headers. Therefore, if the disk is lost in an unforeseen scenario, it may be simpler to restore boot data.

Something you need to pay attention to is that, not all Windows OS support GPT style. Here we make a list to help you:

Only 64-bit systems (including Windows Server) can use GPT disk as system disks, except for Windows XP x64 Edition, which can only use GPT disks for data.

How to initialize a new SSD as MBR or GPT

After you read some basics about MBR and GPT, now it’s time to choice.

On the whole, the GPT style is more resistant to faults and provides greater security. And due to the different structures of HDD, SSD can boot the system faster, and it won’t produce fragmentation. If your SSD is larger than 2TB, and your devices support UEFI boot mode, you can initialize SSD as GPT and set it as a system disk. Of course, the OS you’re going to install should support GPT as the boot disk.

If your devices don’t support UEFI boot mode, or you’ll install a 32-bit system, MBR is also a nice choice.

When you plug your SSD, you won’t see it in File Explorer, you can find it in Disk Management which will show the whole disk as unallocated space. If Disk Management doesn’t detect this disk, you can also use BIOS to see the disk information and check whether the SATA port is enabled or not. In addition, BIOS can’t initialize a disk, after you adjust the port, you need to go back to Disk Management to finish the initialization.

Here’re steps about how to initialize an SSD:

Step 1. Right-click the “This PC” icon on the desktop, and choose “Manage”. In the Manage window, click “Disk Management” under the storage.

Step 2. Right-click the unknown disk that is the target SSD, and select “Initialize Disk” in the menu.

Step 3. In the window, choose MBR or GPT for SSD, and click “OK”.

Then your new SSD is ready to be formatted to NTFS or FAT32, and then you can use your SSD normally.

Further reading: Change between MBR and GPT without reinstalling and data loss.

Although the initialization of a disk is the first step when you set a new disk up, it’s not an irreversible operation after you selected the partition style. The conversion between MBR and GPT is one of the common disk management for many users. For instance, some may wish to use a 3TB disk, since MBR only supports 2TB, the disk will need a conversion to change into GPT. Or some wish to install an OS that only supports GPT disk as a boot disk, like Windows 11, but the target disk is an MBR disk, thus, it’ll be converted to a GPT disk

Whatever the reason is, you can convert the partition style when it’s necessary. The problem is how to convert. Windows has tools to assist users to convert, both Disk Management and Diskpart can convert data disk from MBR to GPT or GPT to MBR. But, they only work on an empty disk, and only a data disk, which means they will delete all on the target disk.

If you’re a Windows 10 V1703 or later user, you can use MBR2GPT to convert only the system disk, and only from MBR to GPT. After the conversion, you’ll need to reinstall the system.

Thus, we suggest you choose reliable third-party software to do this job for you. AOMEI Partition Assistant Professional is a highly-recommended tool we’d like to show you. It can convert system disk and data disk between MBR and GPT, and the best thing is that it won’t ask for deleting data. So you don’t need to reinstall OS and other installed programs.

The conversion will be done in 3 steps, after that, you can reboot your PC to set your boot mode if you convert a system disk.

Step 1. Install and run AOMEI Partition Assistant Professional. Right-click the disk and choose “Convert to GPT" or click the disk and choose "Convert to GPT" from the right column. In the example, we convert a system disk.

Step 2. Click “OK” to confirm your operation.

Step 3. Click “Apply” to commit the pending operation.

Then you can go to BIOS to change boot settings.

Final words

After this article, you know how to initialize an SSD as MBR or GPT, and how to change from MBR to GPT or GPT to MBR when it’s necessary.

AOMEI Partition Assistant can also do the initialization job for you, so you can easily set your target disk up for the next step. It also has other practical functions like “Migrate OS to SSD”, “App Mover”, “Disk Clone Wizard”… and it can serve Windows Server users with its Server edition.