antecedents

Since the hard disk of iMac is a mechanical hard disk, software running often suffers from lag, so I thought of whether it is possible to install the system into a mobile hard disk like Win to Go. I tried it out and found it was totally doable, but if it was a mechanical hard drive, it would still stall, and if it was a solid state drive, it would be much better, and the Mac just took off.

The required items

  • A mobile SOLID-state drive (I used a Samsung T5, 1T).

process

  • Modify the partition table format. Samsung T5 default MBR format, need to convert to GUID partition table format;
  • Startup press Command + R;
  • Select the Disk Tool, erase the removable hard disk, and set the format to APFS;
  • After successfully erasing the MAC OS, return to the utility screen, click reinstall MAC OS, and follow the normal installation process as prompted.

Matters needing attention

  • After the installation is successful, the system of the removable hard disk is displayed by default. You do not need to select the system or hard disk every time. To switch to the original system, hold down the Option key when starting up the system.
  • The removable hard disk still functions as a removable hard disk, but it is different from a normal removable hard disk according to the file hierarchy of the MAC system. Therefore, when reading and writing files, you should put them in a familiar place for easy searching.

knowledge

  • Samsung T5 SSD uses MBR format by default. You need to convert the partition format to GUID partition table format.
  • The MBR format can only be MAC OS extension (log format).
  • GUID partition table format can be formatted as APFS.