What's the Best Drive for Mac Time Machine Backups?

Sourced from real discussions on r/mac and r/applehelp, cross-checked against live PricePerGig listings.

The best drive for Mac time machine backups is a big drive! You want a large HDD that’s at least twice the size of your Mac storage, ideally three times. A lot of advice online points you towards SSD drives, and yes, great but these were clearly written before StorageApocalypse and RAMpocalypse, and realistically Time Machine backups happen in the background, when you’re not doing a lot so it doesn’t matter if it takes another few minutes.

If you’ve got a base macbook with 256GB storage then yes a 1TB SSD drive used to be ideal, they are small, ‘drop resistant’ and easy to stick in a drawer (possibly too easy, I’ve lost one in the past), but at around $100 per TB, that’s pricey, you can get a small portable 2.5” hard drive for half that with the same capacity.

If however you opted for a larger storage drive on your Mac, now the cost really adds up, and you want a large drive to have multiple copies of your changed files, many times when I’ve tinkered just a bit toooo much, I’ve needed to go back to before a change I made, and no, I didn’t realise immediately, so that multi week backup is needed at times.

Another thing to consider with Time Machine backups is are you plugging the drive in? or accessing over a network via a NAS or similar? If it’s over a network, the bottleneck is right there, not the drive itself, so again, big, cheap drive is needed here.

The only time having SSD vs HDD will impact you is during restore, an extra few minutes, and only if you are plugging it directly in to the Mac anyway, so go for a large external USB drive. So, at this point you’re onto a multi TB external drive, go for a known brand like WD or Samsung or UGREEN and leave it on your desk.

The table above compares the live price per TB for USB-C external hard drives on your marketplace, the portable 2.5 inch size against the roomier 3.5 inch desktop size, which is the whole decision in one table.

Why a hard drive, not an SSD

This is where people overspend, so let me stop you.

Time Machine works away in the background, snapshotting your files over time. You are almost never sitting there watching it or waiting on it.

That means SSD speed is completely wasted. You would be paying several times more per TB for performance your backups never use.

A big cheap hard drive is the right tool. Put the money you save into more capacity, which Time Machine actually benefits from.

How big should it be?

Here is the rule that makes Time Machine shine.

Buy a drive several times bigger than the data you are backing up. Two to three times is a good target.

Why so big? Because Time Machine does not just keep one copy. It keeps a history of older versions, so you can roll back a file to how it looked last week or last month. The more space you give it, the deeper that history goes.

You do not have to take my word for how much history it keeps. Here is macOS Tahoe 26.5.2 describing it in its own settings panel:

Time Machine backs up your computer and keeps local snapshots and hourly backups for the past 24 hours, daily backups for the past month and weekly backups for all previous months. The oldest backups and any local snapshots are deleted as space is needed.

Read that last sentence again, because it is the whole argument for buying big. The oldest backups are deleted as space is needed. A small drive does not fail, it just quietly shortens your history until the version you wanted is already gone.

So a generous drive is not waste here. It directly buys you a longer, more useful backup history. Check the live table and size up.

What to actually buy

Keep it simple.

• A large external hard drive, sized two to three times your data.
• Plug it in, point Time Machine at it, and let it run.
• Buy on the best price per TB from the live table above, because capacity is the whole game.

A plain, roomy external drive does this job perfectly. No need for anything fancy or fast.

Do not stop at one copy

A gentle but important nudge.

Time Machine on a local drive is a great first backup. But it lives in the same house as your Mac.

For anything irreplaceable, add a second copy somewhere else. A cloud backup or a drive kept offsite means a fire or theft does not take both your Mac and its backup at once.

Time Machine plus an offsite copy is a genuinely solid setup.

The bottom line

The best Time Machine drive is a big, cheap external hard drive, sized a few times larger than your data so the version history has room to breathe.

Skip the SSD, chase the best price per TB on the live table above, and add an offsite copy for the irreplaceable stuff. Cheap, roomy, and your Mac is properly protected, no fuss and no overspending.

So now you have it, the full ‘how to choose the best drive for your time machine backups’

Base Mac - simple 2.5” portable spinning drive with USBc connector

Upgraded Mac - cheaper per TB 3.5” external drive with USBC connector

← Back to the Hard Drives (HDD) hub