Can I run clone of new MBP on old MBP?

[aeterno]

Laptop 1:
MacBook Pro 2017
10.13.4
2.9GHz
16GB RAM

Laptop 2:
MacBook Pro Mid 2012
10.8.5
2.6GHz
8GB RAM

If I clone Laptop 1's SSD to an external drive via Carbon Copy Cloner before I send it in to Apple for a week for various repairs, will I be able to run it externally on Laptop 2 without any major issues? I've cloned before and booted from that externally, but only on the same laptop. Wondering if there would be any incompatibilities trying to run a clone from a new machine on an old one.

 

[velocityg4]

It should work. There might be licensing issues with some paid software. As your Mac is different.

 

[chrfr]

Laptop 1:
MacBook Pro 2017
10.13.4
2.9GHz
16GB RAM

Laptop 2:
MacBook Pro Mid 2012
10.8.5
2.6GHz
8GB RAM

If I clone Laptop 1's SSD to an external drive via Carbon Copy Cloner before I send it in to Apple for a week for various repairs, will I be able to run it externally on Laptop 2 without any major issues? I've cloned before and booted from that externally, but only on the same laptop. Wondering if there would be any incompatibilities trying to run a clone from a new machine on an old one.

There have been many firmware updates for security and to add new features over the years which are included in the macOS installers and updaters. You may run into some problems because of the old firmware version on the 2012 MacBook Pro. The fix is a bit complex, but you could clone the computer, then just run the high Sierra installer on the external disk. That will update the firmware on the 2012, but as long as you make sure you point the installer to the external disk, the 10.8.5 installation will be intact. Alternatively, you could just upgrade the internal disk on the 2012 to High Sierra. (You probably should be running 10.13.6 and subsequent security updates rather than 10.13.4, even on the 2017.)