I’m going to buy a used 2015 MacBook Pro and I want to upgrade the ssd but I don’t wanna keep any data cause it’s used so I guess there’s no need to. Do I need to back up anything? Is it necessary to use an enclosure ? And do I have to save the os or something like that ?
The Retina Apple laptops use a proprietary Apple PCIe SSD connector so you will need to get an OWC Aura SSD.
https://eshop.macsales.com/shop/ssd/owc/macbook-pro
These third party SSDs are NVMe based SSDs which require that the laptop first has macOS 10.13+ installed on the original Apple SSD so that the laptop has the necessary system firmware to work with a third party NVMe SSD. You will also need to install macOS 10.13+ on the third party SSD on this laptop as well because only macOS 10.13+ has the necessary NVMe driver.
I highly recommend keeping the original Apple SSD since it may be needed later on to update the laptop's system firmware or to install macOS. I would definitely erase the SSD to remove anything from the previous owner even if you don't intend to use it. OWC sells external enclosures so you can use the removed Apple original SSD.
You have to be extremely careful buying a used Mac unless you buy a refurbished system direct from Apple. If the previous owner has their AppleID associated with the Mac, then they can still control it by locking you out of the Mac with FindMy. The previous owner may have enabled a firmware password which means you will never be able to remove the lock or the laptop may still be controlled by an MDM from a school or business. The thing to do is perform a clean install of macOS which will detect many of these things during the install & setup process. You should also try to add the Mac to your AppleID.
The first thing I would do is to perform a clean install of macOS on this laptop by first erasing the whole physical drive using Disk Utility before re-installing macOS. This will do several things for you. It will let you know if there is a firmware lock on it (very bad), and it give you a fresh clean file system & OS. Plus when going through the initial setup with Setup Assistant on the clean install it will tell you whether the laptop is being managed by an MDM from a school or business (also very bad).
If macOS 10.12.6+ has been previously installed on this laptop, then you have access to Internet Recovery Mode (Command + Option + R) to access the online macOS installer (I prefer Internet Recovery Mode over local Recovery Mode since it is not booting from the local drive since it is a pre-owned system). Or you can create a bootable macOS USB installer using the instructions in this Apple article:
https://support.apple.com/en-us/HT201372
With later versions of macOS (10.13+) Disk Utility hides the physical drive from view by default. This Apple article has a section showing how to reveal the physical drive within Disk Utility:
https://support.apple.com/guide/disk-utility/erase-and-reformat-a-storage-device-dskutl14079/mac
FYI, here is what the previous owner should do before getting rid of their Mac:
The Retina Apple laptops use a proprietary Apple PCIe SSD connector so you will need to get an OWC Aura SSD.
https://eshop.macsales.com/shop/ssd/owc/macbook-pro
These third party SSDs are NVMe based SSDs which require that the laptop first has macOS 10.13+ installed on the original Apple SSD so that the laptop has the necessary system firmware to work with a third party NVMe SSD. You will also need to install macOS 10.13+ on the third party SSD on this laptop as well because only macOS 10.13+ has the necessary NVMe driver.
I highly recommend keeping the original Apple SSD since it may be needed later on to update the laptop's system firmware or to install macOS. I would definitely erase the SSD to remove anything from the previous owner even if you don't intend to use it. OWC sells external enclosures so you can use the removed Apple original SSD.
You have to be extremely careful buying a used Mac unless you buy a refurbished system direct from Apple. If the previous owner has their AppleID associated with the Mac, then they can still control it by locking you out of the Mac with FindMy. The previous owner may have enabled a firmware password which means you will never be able to remove the lock or the laptop may still be controlled by an MDM from a school or business. The thing to do is perform a clean install of macOS which will detect many of these things during the install & setup process. You should also try to add the Mac to your AppleID.
The first thing I would do is to perform a clean install of macOS on this laptop by first erasing the whole physical drive using Disk Utility before re-installing macOS. This will do several things for you. It will let you know if there is a firmware lock on it (very bad), and it give you a fresh clean file system & OS. Plus when going through the initial setup with Setup Assistant on the clean install it will tell you whether the laptop is being managed by an MDM from a school or business (also very bad).
If macOS 10.12.6+ has been previously installed on this laptop, then you have access to Internet Recovery Mode (Command + Option + R) to access the online macOS installer (I prefer Internet Recovery Mode over local Recovery Mode since it is not booting from the local drive since it is a pre-owned system). Or you can create a bootable macOS USB installer using the instructions in this Apple article:
https://support.apple.com/en-us/HT201372
With later versions of macOS (10.13+) Disk Utility hides the physical drive from view by default. This Apple article has a section showing how to reveal the physical drive within Disk Utility:
https://support.apple.com/guide/disk-utility/erase-and-reformat-a-storage-device-dskutl14079/mac
FYI, here is what the previous owner should do before getting rid of their Mac:
ssd upgrade on MacBook Pro without saving the data
