For years I've been cloning MBP's (spinning drives) to FW 800 drives (spinning drives).

I may soon enter the world of Thunderbolt 3 (USB-C) with a 2017 MBP 15, having a 1TB PCIe-base SSD. ...Given the MBP only has USB-C ports, I'm considering using a G-Tech G-Drive USB-C External (7200rpm) HD for clones.

Can a PCIe-based SSD be cloned to an external, spinning drive (like the G-Drive)?

Can anyone confirm Superduper! v2.9.1 (macOS 10.12.3 compatible) will clone and the result will be bootable, enabling a reinstall of the external clone (from a spinning drive) back to the internal SSD? (I've emailed Dave Nanian; so, I'll update when I receive his reply.)

My 2010 MBP had a self-installed SSD, and I used Carbon Copy Cloner to both clone to, reinstall from, and boot from a spinning rust drive in an enclosure...no problems, and with one (still unsolved, I believe) exception, no FTMer has ever reported any problems using SuperDuper! similarly.

There's one caveat, though, which is that SD! cannot clone a recovery partition while CCC can.

I was the exception. For reasons unknown, my SD clone of Sierra works fine although I couldn't boot it in El Capitan. My SD clone is on a spinning drive connected via Thunderbolt and it is a clone of my internal Fusion drive. I also have two external SSD clones that are made via CCC, also via Thunderbolt.

Here's Nanian's reply:
"Sure. If it's formatted HFS+, we're happy to copy it. The way the drive is "implemented" (SSD vs. HDD) doesn't matter.
--
Dave Nanian
Shirt Pocket"

I was unsure about whether there was something unique about cloning SSDs, and I knew I'd get knowledgeable answers at FTM. ...Thanks to all for the replies.

As a follow-up, SD! will no doubt have to be updated when the APFS file system ( says it's written with SSDs in mind) is implemented, replacing the HFS+ format, sometime this year.

Data is cloned based on a "logical" structure and the actual physical storage structure is carefully hidden by the drive's electronics. That way the OS really doesn't care if the physical media is an SSD, Thumb drive, rotating rust, or whatever. The various specifications, such as ATA, SATA, PCIe, etc., define an interface that specifies what information and the OS sends to the drive when writing and what information the data OS will receive from the drive when reading. It is the task of the drive developers to write the firmware that enables the drive to conform to that interface and keep the actual physical layout and organization totally invisible to the OS and applications including CCC and SuperDuper.

Does that mean that the cloning apps won't need to be rewritten?

And how does it relate to the drives we're running today, i.e. will we need new drives?

YES because they operate at the "logical" level not the physical and are therefore unconcerned with the actual physical storage on a drive.
I am not sure how to answer that.

• If you mean will today's SSDs work with APFS the answer is YES
• If you mean will you need new drives for added speed then the answer is a qualified YES.
• If you mean will you need to replace rotating rust with SSD to work with APFS the answer is NO but on a rotating rust drive HFS+ may provide faster I/O but I can't verify that either way.

Here's an iMore article, providing a layman's overview:

APFS

All bases covered.

Thanks!

as long as you're making an accurate clone, the media the system is on shouldn't matter.