Question regarding superdrive replacement and storage placement

[Rockoar]

I know this is a (quite) frequently asked subject but I considered that my question was not answered on previous threads (which I searched through the Forum search function) so I'm hoping you guys can help me out.

Here's my set of questions:

1) When replacing my MBP13 (mid-2012) Superdrive in order to upgrade my Mac storage capacity, where should I put the SSD: in the Superdrive slot or in the original HDD bay?

I'm asking this because I've read that the HDD bay supports better transfer speeds than the Superdrive bay. A quick check on "About my Mac" shows me that my Mac HDD bay supports 6 Gigabit of Link Speed and 3 Gigabit of Negotiated Speed Link, whereas the Superdrive bay speeds remain the same for the Link Speed but decrease to 1,5 Gigabit for the Negotiated Link Speed.

2) Once I've installed the SSD and upgraded my storage, which way would be the best in order to simplify managing two internal discs: creating a DIY Fusion Drive, simply moving my user folder to the HDD, or any other method…?

This last questions is concerning how could I proceed to make my Mac think that both discs are just one, in order to not having to manage files/folders/etc. things manually.


Thank you very much in advance. Hope I was clear enough when writing down my questions, if there's any additional information that I could provide to help you better understand my questions, please don't hesitate to ask.

 

[keysofanxiety]

1) Original HDD bay. On the 2012 systems it shouldn't really matter as both are SATA III/6Gb, but I'm a stickler for tradition. There would be no benefit to putting the boot drive where the ODD went, other than to bypass a faulty SATA cable or something.

2) Fusion Drive. Fuses both drives into one logical volume, meaning one less thing to think about. Let the OS do the work.

You can backup to Time Machine and then restore that to the Fusion Drive, if you want your computer exactly as you left it.

 

[Rockoar]

1) Original HDD bay. On the 2012 systems it shouldn't really matter as both are SATA III/6Gb, but I'm a stickler for tradition. There would be no benefit to putting the boot drive where the ODD went, other than to bypass a faulty SATA cable or something.

2) Fusion Drive. Fuses both drives into one logical volume, meaning one less thing to think about. Let the OS do the work.

You can backup to Time Machine and then restore that to the Fusion Drive, if you want your computer exactly as you left it.

Just to be clear, you're recommending that I swap the HDD to the ODD bay and put the SSD in the original HDD bay…?

And just one more question –seeing that it looks like you have done this–, when creating a Fusion drive, will the OS automatically put/install the OS (macOS, apps, etc.) on the SSD? I'm asking because after creating the Fusion drive, I understand that only that drive will show up, so I'll not be able to choose to place things either on the SSD or HDD. Thanks.

 

[keysofanxiety]

Just to be clear, you're recommending that I swap the HDD to the ODD bay and put the SSD in the original HDD bay…?

Yep.

And just one more question –seeing that it looks like you have done this–, when creating a Fusion drive, will the OS automatically put/install the OS (macOS, apps, etc.) on the SSD? I'm asking because after creating the Fusion drive, I understand that only that drive will show up, so I'll not be able to choose to place things either on the SSD or HDD. Thanks.

Pretty much. macOS will juggle most used applications/the OS itself to the SSD partition and less used apps/files/plugins/gratuitous videos to the HDD. If you then begin to use an application or file more often, it'll move it to the SSD partition. It does it all under the hood. It's a bit disconcerting to sometimes put your feet up and trust the OS is sorting stuff out for you, but that's basically how it works. So you needn't interfere or worry about any maintenance.

 

[Sanpete]

Besides not letting you decide what goes where (which as @keysofanxiety points out is fine if you don't want to hassle with that), another thing to consider about the homemade fusion drive is that the reliability of both drives is lowered to that of the less reliable. If one fails, your data is lost. If you're backing up anyway, that may not matter.

I think I've seen complaints about other issues with the fusion-linked drives too, that they sometimes become de-linked, for example, in which case you also lose your data. Might be worth googling about.