Transfer SSD from one MBP to another

Trust me, you're not alone! I have been guilty of this myself. 😊 ... or at least, I had the backup, but didn't verify that is was still good ... just as useless as not having one. Fortunately, it wasn't a critical situation and I was able to "survive" the mistake ... but I now diligently make multiple backups and periodically test them. Lesson learned for me.

Something that came to mind. You could try placing your 2011 SSD into a USB drive caddy. Then connect it directly to your new MBP when it arrives and hold down the <option> key at boot up to select this drive to boot from. If your new Mac boots up successfully with this drive, then it should be "good to go" to replace the existing 2012 drive with it.

Macs cannot boot from any OS version older than what they came with. IF your old SSD has an OS version newer than what the 'new' 2012 comes with, you should be able to do it. Is this 2012 an Apple refurb or ??? I got one of those last year and it came with Sierra (although it originally had Mavericks on it) - I was able to get Mavericks installed on it because that was the original OS.

Hi,

I think simply install old 17-inch SSD into 15-inch 2012 MacBook Pro is working if 17inch SSD is not damaged.

I wouldn't think hardware has anything to do with that; if it did, how can you pop a new SSD into an older Mac and it'll work?

The OP was asking can you simply swap the drives. As you know, you can physically replace one SSD with a similar SSD. That's not an issue. But if that replacement SSD was pre-installed in other computer, the OS on that SSD would be configured to work with the hardware on that computer. Unless the new computer is identical (or very similar) hardware-wise, there are going to be configuration problems.

As I mentioned to the OP. Normally, when you are migrating to a new non-identical computer, you would rely on Migration Assistant on the new computer to restore from a Time Machine backup of the old computer. That's because, the new computer would already have the OS installed that is configured to work with that computer's hardware and you just want to make it "work like the old one." This is different than just swapping in a new drive to replace an existing one on the same computer.

So to directly answer your question. I would first clone the older Mac's system drive (SSD or HDD) to the new SSD, where the new SSD was placed in a drive caddy and attached to the older Mac. Once the clone is done, I would test it by booting up the older Mac with this drive. If successful, I would go ahead and swap the drives.

This is a very confusing issue, but these subtle rules apply:

A version of MacOS that is OLDER than the original-release software for a particular model Mac cannot possibly run on that Mac, because the newest drivers for its new hardware are not included. (Also, you must use release numbers, like 17E56 not just revision numbers 10.13.2 to make a completely accurate assessment.)

The instance of MacOS that "shipped in the box" with a specific computer works with that model only -- it does not have "drivers for every appropriate model Mac" so will not run on different models. Any updates you perform on that MacOS software, including re-install of the same major version, will still have only drivers for that model Mac.

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For Mac OS X, any version "purchased" (even for $0) and tagged with your Apple-ID will have Drivers for every appropriate model Mac. MacOS X default is to install all drivers into the system directories, and selectively load the ones needed at Startup Time.

[The Master Installer "Full Retail" CD/DVD version for purchased OS9 also contained all drivers, but the Installer default was to install for a specific Model Mac, and the option to install the bigger version with "drivers for every appropriate model Mac" was there only as an option, and difficult to access directly. So OS9 drivers were generally selected at Install-time, unless you took pains to do it the other way.]

Unfortunately, you cannot simply swap the drives for one potential reason: The 2011 MBP SSD was configured to work with your 2011 MBP's hardware and not with any other hardware configuration. On the other hand, if you were simply replacing the SSD with a new one in the same notebook, that would be a relatively easy swap.

Normally, when you get a notebook that is not the same model as the current one, you would rely on restoring from a Time Machine backup by using Migration Assistant on the new device. Do you have any current TM backups of your 2011 MBP?

The 2011 MBP SSD was configured to work with your 2011 MBP's hardware and not with any other hardware configuration.

Out of curiosity: I always thought that SSD is SSD and hard drive is hard drive; they were configured to work with a certain initial OS version, but other than that, I don't quite understand why - if the OS versions are ok - it could not be swapped. I wouldn't think hardware has anything to do with that; if it did, how can you pop a new SSD into an older Mac and it'll work?

But if that replacement SSD was pre-installed in other computer, the OS on that SSD would be configured to work with the hardware on that computer.

I am bowing out of this conversation since, in all the years I have worked with Macs, I have never heard of that.

Thanks for the very thorough explanation.

A version of MacOS that is OLDER than the original-release software for a particular model Mac cannot possibly run on that Mac, because the newest drivers for its new hardware are not included. (Also, you must use release numbers, like 17E56 not just revision numbers 10.13.2 to make a completely accurate assessment.)

Yes, I was/am aware of it; unfortunately, Apple either pulled the article (or hid it because I have not been able to find it) which included build numbers. I wish I had downloaded that. In any case, it was very helpful since it showed all the build numbers every model (and subsequent releases) a Mac came with.

The instance of MacOS that "shipped in the box" with a specific computer works with that model only -- it does not have "drivers for every appropriate model Mac" so will not run on different models. Any updates you perform on that MacOS software, including re-install of the same major version, will still have only drivers for that model Mac.

I was aware of that with any Mac that came with install media in the box. However, this could have been about either an early or late 2011 (with either an install disk or a Lion download, which we do not know) and the OP was able to use the SSD - which I assume was the OEM drive - in a different model/year MBP and it worked. So, according to your explanation, this had to be one with Lion installed (a late 2011).

Glad to hear that worked (just as I thought it would as long as there was no problem with the OS versions).