OWC ThunderBlade: macOS Boot Drive Setup

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Relevant Part Numbers

  • OWCTB3TBV4T1.0
  • OWCTB3TBV4T2.0
  • OWCTB3TBV4T4.0
  • OWCTB3TBV4T8.0


Please note that it is not possible to use the ThunderBlade or ThunderBlade X8 as a macOS boot volume when in its default configuration of a RAID 0. In order to accomplish this, the RAID must be deleted using SoftRAID, so that one of the four M.2 drives installed can be assigned as a separate, independent mode boot volume. WARNING: this process will delete all data currently stored on the drive! Make sure you have a backup of any important data on your ThunderBlade or ThunderBlade X8 before proceeding with the steps shown below.

Thereafter, the three remaining M.2 drives can be reset in SoftRAID as a new RAID 0 volume. When this process is complete, connecting the ThunderBlade or ThunderBlade X8 to your Mac host computer will result in two volumes appearing in the macOS Finder (and Desktop if your preferences are set to show mounted volumes). This process assumes macOS 10.13 or later is being used (to meet the device requirements). Note: Using the ThunderBlade or ThunderBlade X8 as a boot drive in Windows 10 is not supported.


  1. Download and install SoftRAID if you have not done so already. Note that the installation will likely update the SoftRAID driver that ships by default with macOS, and will require a restart. Note: OWC recommends the latest SoftRAID release for use with the ThunderBlade or ThunderBlade X8.
  2. Launch SoftRAID.
  3. Find the ThunderBlade or ThunderBlade X8 RAID 0 volume in the Volumes section of the app window (right column).
  4. Right-click on the ThunderBlade or ThunderBlade X8 volume and choose 'Disable Safeguard.'
  5. Right click the volume a second time and choose 'Delete.' Confirm the choice when prompted.
  6. There should also be four separate disks in the left column labeled 'OWC Mercury M.2 SSD' for Gen 1 ThunderBlades | 'OWC Aura P12' for Gen 2 ThunderBlades | 'OWC Aura Pro III' for Gen 3 ThunderBlades (ThunderBlade X8).
  7. Select the four disks, right-click and choose 'Zero Sectors'. In the option dialog that appears choose the 'First and Last 100' option.
  8. When the Zero Sectors process is complete, quit SoftRAID then and launch Disk Utility. Disk Utility should display the four M.2 disks in the ThunderBlade or ThunderBlade X8 as four external drives with the same name.
  9. Select one of the disks from the ThunderBlade or ThunderBlade X8 and click the 'Erase' button.
  10. In the dialog that opens, name the volume and make sure the Partition type is set to GUID Partition Table, and that the format is APFS. When ready click the 'Erase' button in the dialog.
  11. When the process is complete click the 'Done' button. At this point you should be able to install macOS on the new volume you just created.
  12. If you wish to continue using the ThunderBlade or ThunderBlade X8 as a high-speed RAID 0 drive (recommended), quit the Disk Utility, re-launch SoftRAID and select the three unformatted ThunderBlade disks, then right-click and choose 'Initialize.'
  13. Once the initialization is complete, with the same three disks selected, right-click and choose 'New Volume.'
  14. In the New Volume window choose Volume Type 'RAID 0,' for the File System choose 'HFS+,' for Optimization choose a setting appropriate to your workflow, then give the volume a name.
  15. Click the Create button. When the Stripe Unit Size dialog appears we recommend you change the setting to 128K and click OK, unless you have a specific reason not to. The process of creating a new volume may take a minute or two depending on the volume size.
  16. If you do not need to use your new RAID 0 volume immediately, to ensure it is functioning properly, right-click the new volume (in the Volumes column) and select 'Validate'. This process may take up to an hour to complete.
  17. At this point you can quit SoftRAID and begin the process of downloading and/or installing macOS to your new ThunderBlade or ThunderBlade X8 boot volume, as you normally would with any other drive.

NOTE: Please be aware that changing from a four drive RAID 0 to a three drive RAID 0 can decrease performance of the volume by as much as 25% depending on drive type and capacity.

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