External HDD as a boot drive?
External HDD as a boot drive?
I think if it needs its own power adapter, it’s likely a 3.5" device with a standard SATA port, such as this one. However, there are numerous external drives—mostly portable or slim—that connect only via USB, like this one. The best approach would probably be to test it yourself.
Sometimes the system shows green drives on the inside, but I can switch to a green drive without any issues.
I haven't encountered anything similar before, yet I'm receiving the expected speeds from my WD Green drive that came from an external HDD. Not impressive speeds overall, but it meets WD's performance claims, making it sufficient for use as a boot drive.
I mounted a 1 tb drive as a boot drive for my MBP for a few weeks after the internal HDD failed. It functioned fine, though it was somewhat sluggish.