I'm looking for recommendations an external drive to use as a time machine backup for my 2021 MacBook Pro with a 2TB internal drive, currently running Sonoma 14.5. I would like to back up before I perform an OS upgrade. I figure 4TB would be a minimum size. Is an SSD or HDD better suited for this, or does it matter?
MacBook Pro (M1 Max, 2021)
SSD unless you already have a HDD. The downside of a HDD is Time Machine will automatically format a new drive to APFS which is debatably not as friendly on HDDs. SSD will also be faster, although with background backups that shouldn't be much of a concern. The downside will be a SSD of the size on which you are planning will not be cheap (a reason why some still go with HDDs).
If you do go with a HDD, make sure it is not a SMR type.
SSD unless you already have a HDD. The downside of a HDD is Time Machine will automatically format a new drive to APFS which is debatably not as friendly on HDDs. SSD will also be faster, although with background backups that shouldn't be much of a concern. The downside will be a SSD of the size on which you are planning will not be cheap (a reason why some still go with HDDs).
If you do go with a HDD, make sure it is not a SMR type.
I recommend SSD for reliability and speed.
Thanks. Are there brands/models of SSD to steer clear of?
In every day use for Time Machine, drive type HDD or SSD makes little difference because the incremental backups that TM makes are usually of small amounts of data and those backups take mere moments or minutes.
Where you are likely to experience improved performance of an SSD vs HDD is in the initial full drive backup of the Mac and anytime when you need/want to recover all of your data from the backup to this or another Mac. Moving large amounts of data can take hours with an SSD, and more hours with a HDD.
Two terabytes of data is getting up where it will take some time to transfer at HDD speeds.
I will choose the SSD myself for these reasons. I am not a patient person and don't like to wait for my tech to keep up with me. 😉
And 4TB for your backup drive is an okay number. Typical guidance says have a b/u drive that is 2x-3x the total capacity of the drive data being backed up.
Time Machine drive recommendations
