Using SSDs larger than 2TB

Crucial SSDs larger than 2 terabytes (TB) can introduce errors if a customer has used a Master Boot Record (MBR) partition structure exclusively in the past, as this structure predates extremely high capacity media and has several limitations which can result in errors until the drive is set up under a GUID Partition Table (GPT). This can also apply when cloning an MBR structure to a new SSD, as that property will be copied and needs to be converted.

Partition Limitations

MBR only allows for a maximum of four primary partitions on a device. Primary partitions can be converted to Extended partitions using third-party software or Windows® Command Prompt to create additional logical partitions, but this can lead to boot problems if attempted on the operating system (OS) partition, and may not be compatible with all applications. We are also unable to provide support for this process, so please refer to support specific to your OS or partitioning software for guidance on this. Because of this, your SSD should be set to use GPT during initialization or at the time you install Windows. Mac® OS users should refer to initialization steps for their OS.

When creating a partition, MBR only allows for a maximum of 2TB of addressable space per partition, and a user will generally be unable to allocate additional space beyond that. Third-party partitioning software may allow the customer to use any remaining space to create additional small partitions to mount as additional drive letters, however this typically requires specialized drivers and additional CPU/memory overhead, so system performance may be reduced, and this configuration may not be compatible with all applications.

Boot Drive Limitations

Based on installed OS, and whether or not UEFI is featured in a system, GPT drives may or may not be supported for both data storage and bootable OS partitions. In general, from Windows Vista on a 32-bit OS will not boot from a GPT disk, but it can be used for data storage. 64-bit versions of Windows will be bootable in a UEFI-based system, and can be used for data storage if UEFI is disabled or not supported.

Converting MBR to GPT

Customers who have a drive configured for MBR and want to convert to GPT have several options.

  1. Convert using diskpart: The Windows Command Prompt tool 'diskpart' can change an MBR disk with no partitions (use the diskpart 'clean' command to wipe the drive using the command prompt first) with the command 'convert gpt'. Due to the need to remove all data from the drive first, users will have to backup important data before proceeding with this process.
  2. Convert in Disk Management: users can right-click the left-most box of the disk view in Disk Management to convert a disk to GPT. As with diskpart, the disk must be empty of partitions and data, or the 'Convert to GPT' selection will be grayed out.
  3. Convert using Disk Utility: Apple® users can change from MBR to GUID Partition Map using Disk Utility. If not done during initialization, the Erase tab in Disk Utility will present this option in a 'Scheme' dropdown menu when reformatting the drive.
  4. Third-party partition or disk management software may allow users to convert to GPT without needing to wipe their drive in the process. We have no recommended tool for this, so please refer to support specific to your partitioning software for guidance and steps on this. Regardless of your choice, to ensure data is not lost by mistake, backup important data before attempting any variation of this.

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