Connecting two Macs in order to migrate data (user files, applications and settings) from one to another is pretty much straightforward and uncomplicated process.
As long as you can find the right cable that links two Macs together, you can start moving files in a few clicks.
Before you start, make sure the storage space in the target computer is large enough to hold the data from the old computer otherwise the migration process will fail.
How to start data transfer to your new Mac
Find the right cable that fits both, your old computer (source) and new computer (target). I will discuss different cables and adapters in greater details later in this post.
Power up your new computer. I assume it has freshly installed OS and boots to the OS X Setup Assistant as shown on the following picture.
If the user account on your new Mac has been configured already, you can force it to re-run the OS X Setup Assistant and start fresh.
Alternatively, you can make a bootable USB install drive and reinstall Mac OS from scratch.
Power up your old computer in Target Disk Mode.
Hold down the “T” key and push on the power button. Keep holing the “T” key down until the Target Disk Mode symbol appears on the screen.
It can be a Thunderbolt or FireWire symbol depending on the type of cable in use.
Follow the OS X Setup Assistant until you get to the “Transfer Information to This Mac” page.
Select “From a Mac, Time Machine backup, or startup disk” option which is NOT selected by default.
On the next page you should see the source hard drive detected by the target computer.
Note: If the source hard drive is not detected, there could be a problem with the source hard drive or file system on the source drive.
On the next page you should see all the information available for transfer to your new computer (user files, applications, computer and network settings, other files and folders).
If you want your new Mac to be configured exactly as the old one, select everything and click continue.
Now just wait until the data transfer is completed.
Now I will discuss different ways to connect one Mac to another.
As an example I will explain how to connect different laptop models but you can use it for iMacs and MacMinis because they have similar ports.
Connecting two MacBook Pros (2008-2010)
The only port available for linking two laptops to each other is the FireWire 800 Port.
In this case you should use FireWire 800 to FireWire 800 cable shown on the following picture.
Connecting MacBook Air (2011-2017) to MacBook Pro (2008-2009)
In this case we run into mismatching ports. One of the laptops has the Thunderbolt port and the other one has the FireWire 800 port.
In order to link these computers to each other you will have to use a FireWire 800 to FireWire 800 cable and FireWire 800 to Thunderbolt adapter.
Connecting two MacBook Pros (2011-2012)
In this case we have two different options available because each laptop has two different ports.
I would suggest using the faster connection link which is Thunderbolt to Thunderbolt cable.
Connecting MacBook Pro (2011-2012), MacBook Air (2011-2017) and MacBook Pro Retina (2012-2017)
All newer laptops have at least one Thunderbolt port (version 1 or 2) available.
Thunderbolt to Thunderbolt cable is the best way to go.
Connecting MacBook Pro Retina (2012-2015), MacBook Air (2011-2017) and MacBook Pro (2016-1017)
In the latest MacBook Pro (2016-2017) models Apple introduced Thunderbolt 3 (USB-C) ports.
In order to connect the latest model to the previous models you’ll have to use a Thunderbolt to Thunderbolt (version 1 or2) cable and USB-C (Thunderbolt 3) to Thunderbolt 2 adapter.
Connecting two latest MacBook Pros (2016-1017)
If you are transferring data between two latest MacBook Pros (2016-2017), you should use the Thunderbolt 3 (USB-C) cable. This cable supports Thunderbolt 3 data transfer up to 40 Gbps.
Do not confuse it with USB-C Charge Cable which looks identical and also works for data transfer but does it at a much lower speed.
Migrating data into new Mac from old hard drive
If your old computer failed but the hard drive is still available and healthy, you can migrate data directly from the hard drive removed from the old Mac.
It’s the exact same data migration procedure as I described at the very beginning of this post (going though OS X Setup Assistant) but you’ll have to use an external hard drive enclosure or adapter instead. Take a look at the following pictures as an example.
Migrating data from 3.5″ iMac hard drive using USB enclosure
Migrating data from 2.5″ HDD/SSD using USB enclosure
Migrating data from MacBook Pro/Air SSD using USB enclosure
If the source SSD has been removed from a newer MacBook Pro/Air laptop, you can use OWC enclosures for Apple SSDs.
Connecting external SSD to latest MacBook Pro (2016-2017)
You cannot connect an external USB enclosure directly to the latest MacBook Pro (2016-2017) with USB-C ports.
You will have to use a USB-C to USB adapter, for example this USB-C Digital AV Multiport Adapter.