Bootable External Drive for Thunderbolt 3 Interface

jphil7747 wrote:

Thanks for taking the time to reply. My basic question is can I configure the USB 3.1 external drive to be bootable. It has to be for the clone to be useable in case of emergency. Since I only use this as an emergency backup it doesn't matter if it's slower than a Thunderbolt 3 drive.

There's no reason why you can't get any external drive to boot whether it's Thunderbolt 3, USB-C (3.1), USB-A (3.0), or even an older USB-A (2.0) drive. You would just need to make sure you use GUID Partition Map for your external drive. A USB 2.0 drive might be painfully slow compared to an internal SSD, but there's no reason why it shouldn't work with an USB-C to USB-A adapter or a hub with USB-A ports.

There are plenty of USB 3 external drives on the market. Some have a native USB-C port, although most would have a common micro-B port. If your "USB 2.0" drive is an external enclosure with a bare drive, then just moving the bare drive to an inexpensive USB 3 enclosure would speed things up.

Here's an external drive that the Apple Store carries:

G-Technology 1TB G-DRIVE mobile USB-C/USB 3.0 Portable Hard Drive - Apple

It's basically a USB 3.0 drive with a common micro-B drive port. I believe it has a 2.5" SATA III bare drive in their custom enclosure. Apple says it comes with a micro-B to USB-C cable, as well as a micro-B to USB-A cable.

What do you normally use to clone?

Thunderbolt 3 is just Apple's version compatible with USB-C. It should be OK although it probably won't be as fast - especially if it's some specialty external SSD.

I've heard of some external drives come with USB-C to USB-micro-B drive cables in the box. You should be able to connect one of those cables to a drive with a micro-B external drive port.

jphil7747 wrote:

No doubt, I'm replacing my old USB 2.0 drive with a USB 3.1 drive to pick up some speed. It's a less expensive compromise to buying a Thunderbolt 3 drive and fine for what I need.

All the newer USB drives themselves are basically USB 3.X so there's not necessarily going to be a performance benefit because it has a native USB-C port.

What kind of external drive do you have? Some people might feel more comfortable taking apart the case and inserting the old drive into an enclosure. USB 2.0 can't keep up with the raw speeds of most hard drives, but a USB 3 enclosure can.

jphil7747 wrote:

Thanks for your response, that's exactly what I needed to know. I've used Super Duper for the last 10 years. It has always worked well for me and maintaining the mirror image on a weekly basis is fast and easy.

Good luck with it. When I wrote "painfully slow" I meant it should work even though it's slow. I think the raw interface bandwidth of the native SSDs that Apples uses for the Retina MBPs is at least 10 Gbit/sec, while USB 2.0 (without accounting for USB overhead) is 480 Mbit/sec. It's going to be considerably slower to be using USB 2.0.

jphil7747 wrote:

I'm fine with just replacing the old drive, in fact, the replacement is on order and should arrive Tuesday. For a USB 3.1 4TB 7200 RPM drive the price was a pretty good deal. Thanks for your suggestions and your advice.

Sure. Personally - I "rolled my own". When my hard drive got corrupted on NYE I went out an bought a 7200 RPM drive as a replacement. When I decided to get an SSD a few weeks later I just used that drive as my new backup in a USB 3.0 enclosure I had. I'll just add that a WD Black 7200 RPM drive is OK, but it's really, really loud.