There’s still nothing as secure as offline storage so we’ve looked at the best external hard drives for Mac for all budgets in 2021.
The great thing for Mac users is that external Hard Disk Drives (HDDs) and Solid State Drives (SDDs) have never been cheaper and storage sizes have never been bigger.
This is good news for those in creative industries that have to handle large files such as RAW photos or high resolution videos 4K that soon eat up valuable disk space.
Or if you’re running out of storage space on your Mac due to large files but don’t want to delete them, using an external hard drive is a great way to free-up disk space.
Less than a decade ago, you would have paid several hundred dollars for a chunky hard drive with just a few Gigabytes (GB) of storage space on.
Now you can get 5 Terabytes (TB) of portable storage (that’s 5000 GB!) for just over $100 such as the Western Digital 5TB My Passport which we chose as the best external hard drive for Mac users of 2021.
However, the external hard drive landscape and technologies is constantly changing and it can be difficult to know where to start when buying one.
And then there’s the question of whether to go for an SSD drive or conventional “mechanical drive”. SSD drives are faster because they have no moving parts but conventional drives are generally cheaper and offer more storage space.
If you’re new to the world of external storage devices, we strongly recommend checking out the section on how to choose an external drive to help you make a more informed decision.
You May Also Like:
- How To Check Storage Space on Macs & Find Large Files
- How To Fully Recover Disk Space on a Mac
- 6 Ways To Speed Up a Slow Mac
- Do Any External Hard Drives Work With Mac?
- What External Hard Drive Does Apple Recommend?
- 1. WD My Passport For Mac (Best Overall)
- 2. Seagate Backup Plus For Mac (Best Value)
- 3. Transcend StoreJet M3 (Best For Photographers)
- 4. WD My Book Desktop (Best Desktop Drive)
- 5. Samsung T5 Portable SSD (Best SSD)
- 6. G-Tech 2TB G-DRIVE Mobile SSD (Best Speed)
- 7. WD My Book Duo Desktop RAID (Best Security)
- 8. WD My Book Thunderbolt Duo (Best RAID Drive)
- 9. OWC ThunderBay 4 Raid (Best Capacity)
- 10. G-Tech Thunderbolt 3
- How To Choose An External Hard Drive
Do Any External Hard Drives Work With Mac?
The good news is almost all external hard drives work with Macs. However, there are some external hard drives which are more compatible with Macs than others.
Most external hard drives use USB ports or USB-3 ports to connect to your Mac but all Macs nowadays have Thunderbolt 3 ports which offer even fast data transfer connections than USB.
Some external hard drives are also already formatted to work out of the box with macOS although most require formatting first.
You can be assured though that all the hard drives featured here are compatible with the latest versions of macOS including Big Sur and Catalina.
What External Hard Drive Does Apple Recommend?
The only officially Apple endorsed hard drive is the Apple Airport Time Capsule.
Time Capsule works over your WiFi connection so the smart thing is, backups are performed wirelessly when used with macOS Time Machine. It’s easily the best wireless hard drive for Mac in terms of compatibility with macOS and arguably the best external hard drive for Time Machine on a Mac.
However, we don’t recommend the Apple Airport Time Capsule for a couple of important reasons.
The main reason is that it’s very expensive compared to other hard drives and don’t get many terabytes for your money.
Backing up via WiFi is also much slower than using an external hard drive connected with either a USB 3.0 cable or Thunderbolt connection.
Unless you specifically want a wireless hard drive, the hard drives we’ve reviewed here are both much better value for money and faster.
With this in mind, here then are the best Mac hard drives and SSDs of 2021 in order of ranking.
We think the Western Digital 5TB My Passport For Mac is the best external hard drive for Mac of 2021 due to a solid combination of reliability, value for money and portability.
It’s ready formatted for use on Mac, Time Machine ready and small enough to fit in your coat pocket.
With a 3 year warranty and big enough to backup all Mac hard drives, if you need a fast, reliable, value for money backup solution for your Mac, you can’t go wrong with the WD 5TB My Passport.
The WD My Passport for Mac supports USB 3.0/Thunderbolt connections but it will also work with older USB 2.0 connections.
We recommend paying that little extra for the 5TB which is the biggest version available in the My Passport Range which ranges from 2TB-5TB.
If you’re going to carry it around a lot, we also recommend getting a proper carry case for it too.
- Very reliable
- Ready formatted for Macs
- Good value for money
- Thunderbolt port
- 3 Year Warranty
- Limited to maximum of 5TB
The Seagate Backup Plus for Mac is the closest rival to the WD My Passport for Mac but offers slightly better prices than its competitor.
The Seagate Backup Plus For Mac ranges from 1TB to 5TB and like the WD My Passport, it’s ready formatted for use on Macs and Time Machine ready for instant backups as soon as you plug it into your Mac.
It also has USB 3.0/Thunderbolt connectors and includes a USB 2.0 adapter cable for older Macs.
The Seagate Backup Plus for Mac also comes with Seagate Dashboard backup software but we found it a bit bloated and hard to customize backups with.
There’s really no need to use it if you’re using Time Machine for your backups.
Although Seagate don’t make it very clear in the product description, the Backup Plus For Mac has a 2 year warranty which is 1 year less than Western Digital.
There’s also a shockproof carry case for it and Seagate are offering 2 months free Adobe Creative Cloud subscription included.
Be aware however that although Seagate has traditionally had a good reputation in the external hard drive industry, more recently there are far more reports of hard drive problems and customer service issues with Seagate external hard drives.
There are also many satisfied customers too but to be on the safe side, you might as well go with WD drives as they’re exactly the same price and in our experience, rock solid.
- Cheaper than Western Digital drives
- Ready formatted for Macs
- Thunderbolt port
- 1 year less warranty than WD drives
- Some reliability concerns
The main selling point of the Transcend StoreJet M3 is that it’s incredibly tough. For those that intend to use a storage or backup device on the move such as photographers, we think it’s the best external hard drive for photographers on Mac due to it’s incredible durability.
In fact, the Transcend StoreJet M3 is military drop tested with an advanced 3 stage shock protection system and a incredibly strong anti-shock rubber outer case.
The Transcend StoreJet M3 also comes with its own software that can be used for one-touch backups.
Just press the button on the Transcend and the software will automatically backup although it also works with Time Machine.
The Transcend StoreJet M3 also comes with an extra USB cable to connect to a second USB port in case your Mac can’t provide enough power for it from one connection although most Mac users shouldn’t need this.
If you’re going to using an external storage device outside, the Transcend StoreJet M3 is a good choice but note that it only comes in a 1TB and 2TB version – there’s nothing bigger.
To enhance protection, you can choose from a range of carry cases too.
- Incredibly strong and durable
- One touch backup system
- No Thunderbolt port
- Limited to maximum 2TB
If you don’t need a portable external drive and are happy to simply have something bigger on your desktop, then look no further than the WD My Book Desktop.
We’ve used WD My Book Desktops for over 10 years and never had a problem and would not hesitate to recommend it still.
Unlike the portable version, the WD My Book Desktop has its own power supply which you connect to the mains so it doesn’t draw any power from your Mac.
It has a USB 3.0 connection port but also works with USB 2.0 ports. Unfortunately it doesn’t have a Thunderbolt port although you can use a USB 3.0 to Thunderbolt converter cable with it.
The WD My Book Desktop also comes with its own WD Backup Software which is straightforward but you really don’t need it if you use Time Machine or another backup software.
For security, the WD MyBook Desktop also features 256bit AES hardware encryption that password protects your data.
The WD My Book Desktop is available in 3TB going up to 10TB.
- Very reliable
- Ready formatted for Macs
- Encryption password protected
- No Thunderbolt port
The Samsung T5 Portable SSD is easily the quietest external hard drive for Mac users we’ve seen.
SSD drives usually offer the poorest value for money in terms of dollars per TB.
They are however extremely fast and silent compared to solid state drives because like your Mac’s internal hard drive, they have no moving parts.
There are very few SSD external drives for Mac that we can strongly recommend but in our opinion, the best consumer priced SSD external hard drive for Mac you can currently get in 2021 is the Samsung T5 Portable SSD.
The Samsung T5 Portable SSD is an SSD external hard drive for Mac with read-write speeds of up to 450 Mbps which is at least twice as fast as most mechanical drives.
It’s incredibly small being not much bigger than a credit card and weighs just 1.8 ounces. It works on Mac, PC and Android devices but note that it’s not ready formatted for OS X.
The Samsung T5 is shock resistant and there’s less chance of it burning-out that a mechanical hard drive because there are no moving parts. In fact, Samsung claims it can withstand 1500G of G-force equivalent to being dropped from 6.5 feet.
It’s also one of the few external drives for Mac that supports USB 3.1 connections. It has a USB-C port which means you can use a Thunderbolt 3 cable with it although it can’t deliver anything close to Thunderbolt 3 transfer speeds.
Note that the T3 comes with a USB-C to USB-A cable in the box.
If you’re looking for incredibly fast transfer speeds, the latest in SSD technology, portability and durability, the Samsung T5 is the one SSD external drive for Mac we would recommend if we had to pick one.
- Super fast SSD drive technology
- Silent hard drive
- Incredibly small and compact
- No Thunderbolt port
If you’re looking for the ultimate in speed, the G-Tech Mobile 2TB G-DRIVE Mobile SSD is the fastest external hard drive you can get for Mac with transfer rates of up to 560 MB/s.
In fact, it’s easily as fast as any MacBook Pro’s internal hard drive so the G-Tech G-Drive Mobile SSD is one of the few external drives out there that lives up to the Thunderbolt 3 billing.
It’s also incredibly durable with IP67 water/dust resistance, 3M drop tested and 1000lb crush resistance.
The G-Tech Mobile SSD has a USB 3.1 Gen 2 connection but also comes with a USB 3.0 Gen 1 cable for backward compatibility.
It also supports Apple File System (APFS) with encryption.
The downside is that like most SSD drives, you don’t get much storage space for your money. The G-Tech G-DRIVE Mobile SSDs are available in 500MB-2TB size but are expensive for such low capacity.
However, if you’re editing lots of video or doing lots of heavy duty creative work in your Mac, the speed and durability of the G-Tech Mobile SSD range can’t be beat.
G-Tech drives also come with a 5 year warranty so you’ll get a replacement drive within 5 years for free if it fails.
- Fastest SSD we’ve tried
- Silent hard drive
- Incredibly small and compact
- Very strong and durable
- 5 year warranty
- Maximum of 2TB storage space
If you want the biggest and best encrypted external hard available on the market in 2021 at consumer prices, then go for the WD My Book Duo Desktop RAID.
The Duo consists of two drives in one enclosure which can be combined as RAID drives to double capacity and speed.
The biggest 36TB drive for example is actually two 16TB WD Red HDDs packed together in one casing.
By combining both drives in one, it offers super fast transfer speeds of around 324 Mbps.
The WD My Book Duo Desktop is the cheapest and most reliable external hard drive for Mac which allows you to choose RAID disks.
RAID (Redundant Array of Independent Disks) is just a way of combining two hard drives into one super hard drive. You can choose between using both drives as RAID 0 (very fast) or RAID 1 (more secure) or divide them both using JBOD. By default, it is configured in RAID 0 but you can easily change it to RAID 1.
If you want to take out or replace on the drives you can also push down on the top of the enclosure and the lid will pop up allowing you to remove the drives.
However, note that you can only use the same drives with the same enclosure. If the enclosure fails for any reason, you can’t just pop out the hard drives and pop them in a new one to save them as each hard drive has a unique encryption key for each enclosure. Enclosure failure is very rare though.
WD SmartWare will automate backups for you and even integrates with DropBox for cloud backups too but you can use Time Machine or any other Mac backup software.
Note that this particular WD hard drive does not come ready formatted for Mac but you can easily format it for Mac in a few minutes using Disk Utility in OS X or by following these instructions.
Although it’s a bit on the pricey side, considering you’re getting two Western Digital 8TB hard drives in one enclosure, it’s actually a very good deal. If 16TB is too big, you can also buy it in models ranging from 4TB to 24TB.
It’s also surprisingly quiet for such a large hard drive and there’s no noisy fan as it’s cooled from the bottom vents with warm air flowing out of the top vents.
- Very reliable
- Surprisingly quiet for such a big drive
- Incredibly fast data transfer rates
- Huge storage capacity
- No Thunderbolt port
Thunderbolt 3 drives are still pretty expensive in 2021 and USB 3.0 offers better value for money with transfer speeds of up to 5 Gbps.
However, if you want a Thunderbolt 1 (10 Gbps) or a Thunderbolt 2 (20 Gbps) external drive for Mac and are willing to pay that bit extra, the WD My Book Thunderbolt Duo is an impressive piece of kit.
The WD My Book Thunderbolt Duo is designed specifically for Thunderbolt 1 connections delivering transfer speeds of up to 10Gbps.
Like the WD My Book Duo, it’s actually two drives combined and has two Thunderbolt connections so that you can access both drives at once if you need to (although note that it only comes with one Thunderbolt cable).
Outside of SSD drives, the WD My Book Thunderbolt Duo is probably the quietest external hard drive for Mac we’ve tried and is ready formatted for use on Mac. It’s also RAID 0 ready although it can be configured for RAID 1 too.
Note though that if just one drive is configured as RAID 0 and the other as RAID 1, you will lose any data on the RAID 0 drive if anything goes wrong so we strongly recommend using RAID 1 on both which treats them both separately even if it does deliver slower performance.
The WD My Book Thunderbolt Duo is only available in 4TB size though.
If you want a reasonably priced Thunderbolt external drive for Mac that quiet and reliable, don’t look any further than the WD My Book Thunderbolt Duo.
- Very reliable
- Thunderbolt port
- Very quiet external hard drive
- Only goes up to 4TB
The OWC ThunderBay Raid is pretty much the fastest and biggest external hard drive for Mac you can get with a maximum of a massive 40TB of storage.
There’s an even bigger model the ThunderBay Raid 8 which goes up to an incredible 128TB.
It’s also one of the only external hard drives to support Thunderbolt 3 which gives incredible top speeds of 1.3Gbps although in reality, you’ll probably get sustained speeds nearing to 827Mbps which is about as fast as it gets for an external mechanical hard drive at the moment.
The OWC ThunderBay also supports RAID 0, 1, 4, 5 and 1+0 meaning you can use each drive separately or combine them for fastest speeds.
The OWC ThunderBay Raid is however one of the most expensive external hard drives you can get for Mac with the largest 40TB of storage costing well over a few thousand dollars.
The OWC ThunderBay is mainly aimed at video editors, enterprises and small businesses that need massive storage and ultra fast rock solid performance.
The Thunderbolt 2 connection is enough for video editors to edit and stream 2K or 4K footage from although note that it doesn’t support Thunderbolt 3.
Like all OWC external drives, the OWC ThunderBay 4 RAID comes with a 5 year warranty which is the longest you’ll find for a quality external hard drive on Mac.
Overall, the OWC ThunderBay Raid is easily the biggest and most reliable external storage drive for Mac available so if you need some serious storage space, it’s the ultimate external hard drive for Mac.
If there’s no availability on Amazon, you can also buy the OWC ThunderBay 4 RAID direct from OWC too.
- Offers the biggest storage space of any external hard drive
- Thunderbolt 3 compatible
- 5 year warranty
- Not formatted out of the box for Macs
G-Tech is a brand of Western Digital aimed specifically at the Macintosh and creative professional market. G-Tech drives are already formatted to use with Macs (although you can re-format them for use with Windows too).
Like most Western Digital products, G-Tech products are reliable, solid and look good.
The G-Tech 4TB Thunderbolt 3 drive can be daisy chained to up to 5 drives and is available from 4-12TB.
If you daisy chained 5 12TB drives that gives you a massive 60TB of very high speed storage space.
The Thunderbolt 3 claim is a bit misleading however. Although G-Tech drives have a Thunderbolt 3 and USB-C port with support for USB 3.1 Gen 1, the reality is it can’t achieve the maximum transfer speed offered by Thunderbolt 3.
This is because inside it’s still only a 7200RPM SATA hard drive which is only capable of delivering transfer speeds of up to 180MB/s whereas Thunderbolt 3 can go up to 250MB/s.
If you really want to get anything close to Thunderbolt 3 transfer speeds, you’ll be better going with a G-Tech SSD drive which is more expensive and have less storage space but because it’s a Solid State Drive, can achieve much faster transfer speeds.
- Made by Western Digital
- Supports Thunderbolt
- 5 year warranty
- Doesn’t fully achieve Thunderbolt 3 speeds
How To Choose An External Hard Drive
With internal Mac hard drives becoming increasingly difficult and expensive to upgrade internally, an external hard drive provides the perfect solution.
However, the technology of external hard drives and the connection port types on Macs have changed a lot in the past few years so it can be quite confusing knowing what to go for, and how to to use them with Macs.
Going for the cheapest hard drives with the most storage space is definitely a false economy in our experience and the loss of your precious data can be priceless.
Generally, the best external storage devices for Mac users fulfill similar criteria to those that are best for PCs but there are some specific things that make some more Mac compatible than others.
Here then are some essential points to consider when buying and using an external hard drive on Mac to help you decide which one is best for you.
Reliability is probably the most important consideration when purchasing an external hard drive for your Mac.
The worse thing that can happen to an external storage device is disk failure.
When this happens, you’ve usually lost everything stored on it which can be a total disaster if you’ve got precious family photos or important documents on there.
Manufacturers rate the reliability of their hard drives with “Annualized Failure Rates“. However, these figures should be taken with a pinch of salt.
Although manufacturers sometimes quote an Annualized Failure Rates of less than 1% (AFR is a percentage of total hard drives sold that fail annually) any figures on reliability aren’t worth basing your decision on in our opinion because everyone uses hard drives in different ways.
For example, those that leave their external hard drives switched on all the time or use it constantly for video editing are going to experience more frequent failures than those that only switch them on occasionally for backups.
Most manufacturers will guarantee at least two years of reliability and the best manufacturers like Western Digital (WD) offer 3 years and OWC offer five year guarantees although in reality, all external hard drives should outlast this with moderate use.
Of course, any such guarantees are little compensation in terms of your precious data in the case of failure. You will have lost all of your files anyway but at least you’ll get a free replacement from the manufacturer.
If you want to learn more about why hard drives fail, you can find an interesting look at hard drive reliability here.
Buy A Decent Brand
This is probably the most important piece of advice when buying an external hard drive.
There is definitely a difference between established brands and lesser known newcomers to the market.
In 2019, the general consumer external hard drive market is dominated by two big players – Western Digital and Seagate – both of which have been in the business over 20 years.
At MacHow2, we use Western Digital (WD) external hard drives on a regular basis and would not hesitate to recommend them such as the extremely reliable WD My Passport range of external hard drives.
Note that Hitachi drives are now owned by Western Digital so if you buy a Hitachi external hard drive, you’re effectively getting a Western Digital product.
There are other brands such as LaCie, Fujitsu and Toshiba but they’re considerably behind the big two when it comes to external hard drive market share and reputation.
Schedule Backups & Usage
Do not use your external hard drive more than is absolutely necessary.
If you have it switched on all day, and particularly if you keep accessing it all day, it’s going to burn out far more quickly than if you just switch it on once daily or weekly to make backups.
Quite simply, the more you use an external hard drive, the quicker it will eventually fail.
Those that edit video on their Mac directly from an external drive can therefore expect their hard drive fail quicker and should definitely invest in higher end quality hard drives featured here such as the WD My Book Thunderbolt Duo or OWC ThunderBay.
Use A Second Backup Solution
If you’re using an external hard drive on your Mac for performing backups, you should consider using a second backup solution.
The chances of two external hard drives failing at the same moment are extremely slim so if your backups are really important, using two drives is the best thing you can do for backups.
If you don’t want to purchase a second drive, alternatively you can make sure you’re using a cloud backup solution in tandem with your external hard drive.
The WD My Book Duo for example also allows you to backup to it’s own Cloud service Western Digital MyCloud although this of course costs extra.
For Mac and iOS users however, the easiest solution is to backup using Apple’s iCloud alongside your external hard drive.
You get 5GB of free online storage with iCloud with plans starting at just $0.99 per month for 50GB.
Get A Power Surge Protector
One thing that can instantly destroy your hard drive is a power surge in your home or office electricity supply.
However, you can easily protect against this with a cheap Surge Protector Power Strip which is well worth the investment (for your Mac too).
Note that a common occurrence with cheaper brand external hard drives is that the inverter inside fails which basically allows too much power to short-circuit and destroy the hard drive.
In these cases, a surge protector won’t help you which is another reason why we only recommend buying an external hard drive from a reputable brand.
Never Move A Drive When Its Switched On
Try never to move an external hard drive when it is switched on.
External hard drives have moving parts which read the magnetic surface of the drive.
There is a danger that the read/write heads can move and make contact with the hard drive in which case, it will break immediately.
The only way to avoid this is to buy a Solid State Drive (SSD) which has no moving parts although there are more expensive and have less storage capacity although this is slowly changing as the technology advances.
The internal hard drive on all new Macs are SSD drives which is why it’s perfectly safe to carry around a MacBook and not worry about damage from movement.
Buy The Most Storage Space You Can Afford
External hard drives now offer massive amounts of storage space and the starting point in most external hard drives is now generally at least 1 Terabyte or more.
1 TB equals 1000GB and is roughly equivalent to 488,000 photos and 220 full length movies so a 5TB hard drive could be enough for a lifetime of photos or music for most people (see the table below).
There’s no right or wrong answer when it asking yourself “how much storage storage space do I need?”. But our advice is simply to buy the biggest you can afford.
Cloud storage solutions such as iCloud and OneDrive are certainly reducing the need for physical storage but the bigger your external storage device is, the more it can grow with you.
As photos and videos increase in size (most high-end digital cameras and even iPhones can film in 4K for example which eats massive amounts of hard drive space) the bigger the better.
Nowadays, 1TB of hard drive can cost less than $100 while one of the biggest consumer priced external hard drives, the WD My Book Duo 20TB, costs around $700.
For those looking for serious storage space for enterprise backups or 4K video editing, the OWC ThunderBay goes up to 56TB but will set you back over a few thousand dollars.
Desktop vs Portable
There are two types of external hard drives for Mac: 3.5 inch desktop drives that have their own mains power source and 2.5 inch portable external drives that take their power from your Mac.
Portable drives will easily fit in your jacket pocket. At the moment, desktop drives go up to a maximum of around 56TB and Portable go to around 5TB.
Some of the biggest desktop external drives such as the WD My Book Duo and OWC ThunderBay are actually a combination of 2 drives in one enclosure which can be used as RAID (Redundant Array of Independent Disks) drives.
This basically means you can combine them both for double the speed, storage and performance.
SSD vs Mechanical Drives
Almost all external hard drives nowadays are still mechanical drives which means they have moving parts inside.
Mechanical external hard drives feature moving parts which can deteriorate and break more easily.
Solid State Drives have no moving parts, are therefore less likely to break and they’re incredibly fast but there are less available and are expensive for the little storage space they offer.
There’s no doubt that SSD drives will eventually replace mechanical drives in the external hard drive market but the economies of scale still aren’t there yet.
All new Macs since 2012 (except iMacs, Mac Minis and non-retina MacBook Pros) have internal SSD hard drives fitted as standard and anyone that’s used older Macs with mechanical internal hard drives will tell you how much faster and efficient SSD drives are.
SSD drives are also silent and run cooler compared to mechanical drives which whir and buzz due to the drive spinning which also creates more heat.
There are also some hybrid drives that are a mix of solid state and SSD drives although these are less common.
As the technology improves, prices come down and capacity of SSD increases, it’s likely that eventually all external hard drives will be SSD drives.
But at the moment, mechanical drives still rule the external drive market and offer the biggest capacities for the best prices.
Currently, we rate the best SSD external hard drive for Mac as the Samsung T5 Portable but you only get 2TB and the list price is $479.99.
External Hard Drive Speeds
The speed of backups or data transfer from your Mac to your hard drive depends on two things – the connection port type (see below) and the hard drive’s physical speed denoted in Revolutions per Minute (RPM).
Most external hard drives are 5400RPM but there are some faster high-end drives that are 7200RPM.
A 7200RPM drive will be faster than a 5400RPM drive because the drive revolves faster and therefore can be read by the drive head quicker.
If you’re connecting a 7200RPM hard drive via a super fast Thunderbolt or USB 3.0 connection, then you’ll enjoy the hard drive’s maximum transfer speed.
However, a 7200RPM mechanical drive can’t achieve anything near Thunderbolt 3 speeds. A good example is the G-Tech Thunderbolt 3 external drive which has a 7200RPM mechanical drive but still can’t achieve the maximum transfer speed of Thunderbolt 3.
The G-Tech 2TB Mobile SSD can however because it’s a Solid State Drive (SSD).
All new Macs have Thunderbolt ports although the number of external hard drives that can take advantage of Thunderbolt speeds is still relatively small.
However, if you’re connecting with an older Mac via a USB 2.0 or Firewire port, then your connection cable won’t even be able to deliver the maximum speed of the hard drive so you might as well save some money and get a 5400RPM with greater capacity than a fast drive with less capacity.
The reality is that whichever hard drive you get, you’ll probably get around 100-200 Mbps transfer speed from most mechanical drives and about double this from an SSD drive.
This is well below the capabilities of most modern connection ports and cables but as we’ll explain shortly, external hard drive technology still hasn’t fully caught up with them.
Our advice is don’t worry too much about hard drive speed on external drives.
Most external hard drives have a USB 3.0 connection which will deliver incredibly fast transfer speeds. Most consumer priced external drives are 5400RPM anyway so it’s not something you can easily be choosy about.
7200RPM external drives tend to be more expensive, noisier and most manufacturers are concentrating on trying to deliver more speed by designing hard drives that can take full advantage of connection types, than hard drive speeds as we’ll see below.
Connection Port Types
The business of external hard drive connections can be extremely confusing as technology changes and Apple seemingly keeps changing ports on every new generation of Mac.
All new Macs since 2012 have ditched Firewire in favor of Thunderbolt 3 connections offering staggering maximum data transfer speeds of up to 40 Gigabits per second (Gbps). Port connection speeds are measured in “Megabits per second” (Mbps) or “Gigabits per second” (Gbps). 1000 Mbps equals 1 Gbps.
However, the problem is that most external hard drives don’t even support the transfer rates of the latest generation of Thunderbolt yet (Thunderbolt 3).
There are some SSD drives however that now do such as the G-Tech G-DRIVE Mobile SSD but it’s expensive and only allows a maximum of 2TB storage space.
There are also high end drives such as the OWC ThunderBay which supports the slightly slower Thunderbolt 2 (20 Gbps) and the WD My Book Thunderbolt Duo which supports the even slower Thunderbolt 1 (10 Gbps).
However, it is USB 3.0 (5 Gbps) that currently dominates the external hard drive market which has superseded the USB 2.0 (480 Mbps) ports that almost everyone has used at some point.
Confusingly, USB 3.0 has now been renamed USB 3.1 Gen 1.
All Macs from 2012 have at least one USB 3.0/USB 3.1 Gen 1 port and two Thunderbolt 1 or 2 ports although the good news is that most external drives with USB 3.0 are also backward compatible with USB 2.0 ports found on all older Macs.
To complicate things however, USB 3.1 Gen 2 (10 Gbps) is also now available which is even faster but faces the same problem as Thunderbolt – there are still very few manufacturers that support USB 3.1.
Firewire meanwhile has pretty much been abandoned by most external hard drive manufacturers although there are a few that still support it.
As you can see, it seems that port connection standards, usually driven by Intel and Apple, are changing faster than external hard drive manufacturers can keep up with but to clarify things, here we’ll take a closer look at the sometimes bewildering world of external hard drive port connections on Mac.
USB 2.0 & USB 3.0
Almost all external hard drives for Mac now use a USB 3.0 port. If your Mac is from 2012 onwards then it will have at least one USB 3.0 port. You can check this by doing the following:
- Go to the Apple logo in the top left of your Mac and select “About this Mac”
- Click on “System Report” on the Overview tab
- Select USB down the left hand margin
There you will see if you have a USB 3.0 port. Macs before 2012 only have USB 2.0 but the good news is that all USB 3.0 external hard drives are backwards compatible with USB 2.0 ports.
The only difference is you will get a maximum data transfer speed of 480Mbps compared to 5 Gbps with USB 3.0 (see the port connection speed comparison table below for an overview of speed differences between connection ports).
USB 3.1 was released a few years ago and offers more than double the speed of USB 3.0 at 10Gbps (roughly the same as Thunderbolt 1). The problem is that most external hard drive manufacturers simply do not support it.
There are some models such as the Samsung T5 Portable SSD which is both an SSD drive and 3.1 compatible but only goes up to 2TB and is quite expensive.
Our advice is, don’t look for a USB 3.1 drive at this stage – the adoption by manufacturers and economies of scale simply still aren’t there.
Thunderbolt 1, 2 & 3 / USB-C
Since 2012, new Macs have Thunderbolt connections. Thunderbolt replaces the older Firewire connections and is now standard in all new Macs.
This is incredibly fast and easily allows you to edit video from your Mac as if it were on your Mac’s internal hard drive or even connect a 4K external monitor to.
Thunderbolt has been developed by Intel and Apple but uses the same connection port and cable type as USB-C which was developed separately by the USB Implementers Forum.
USB-C will eventually replace USB 3.1 although USB-C devices can only handle a top speed of 10 Gbps.
If you’ve got a pre-2016 Mac with a Thunderbolt 2 port, you’ll need a conversion cable from Apple to connect it to Thunderbolt 3 or USB-C ports.
If you’re backing up large amounts of data, a Thunderbolt compatible external hard drive is definitely worth the investment because it makes backups much quicker.
Or if you’re planning on regularly transferring or backing-up 4K video, a Thunderbolt connection makes creating backups and editing in real-time from an external hard drive much quicker.
However, there’s one big problem with Thunderbolt 3 and USB-C.
At the moment, there are still no external drives that actually support Thunderbolt 3.
The closest we’ve found is the OWC ThunderBay which supports Thunderbolt 2 capable of speeds of up to 20Gbps.
Beware that there are some manufacturers that claim to be “Thunderbolt 3” compatible but this is misleading as it merely means it can plug into a Thunderbolt 3 port – it does not deliver Thunderbolt 3 transfer speeds.
Always check the small print what the maximum transfer speed is – if it’s not at least 40 Gbps then it’s not Thunderbolt 3 compatible.
For this reason, at the moment in 2019, we advise against making Thunderbolt a priority when choosing an external hard drive for your Mac for several reasons which can be summarized as:
- External hard drives still haven’t caught up with the speed of Thunderbolt connections. A Thunderbolt port can transfer at a staggering 40Gbps but even the fastest hard drives can’t get anywhere near this.
- There are three types of Thunderbolt – version 1, 2 and 3 each faster than the last. The problem is that those Thunderbolt drives that do exist still use Thunderbolt 1 or 2 which is the slowest standard so you’re not even getting the best that Thunderbolt on the latest generation of Macs can offer.
- Those Thunderbolt drives that currently exist are mainly only Thunderbolt 1 compatible (10Gbps) and expensive for very little capacity compared with USB 3.0 drives which transfer at a very respectable 5Gbps. For example, LaCie offer a 4GB Thunderbolt 1 external hard drive but we would never recommend LaCie drives anyway to Mac users. If you must have a Thunderbolt drive, the best thunderbolt external drive for Mac is the WD My Book Thunderbolt Duo or if you want something really big, the OWC ThunderBay.
Macs before 2012 also have Firewire (400 and 800) ports but this standard is gradually being phased out and we don’t recommend getting a Firewire external hard drive.
The majority of manufacturers that still produce Firewire drives are not established brands either and therefore reliability may also be an issue.
However, if a Firewire port is important for you, we can recommend the well-respected and reliable OWC range of Firewire drives for Mac which support both Firewire and USB 3.0. OWC have been in the business over 25 years.
Apple has replaced Firewire ports on all Macs made after 2012 with Thunderbolt ports.
Note that if the external hard drive has a Firewire connection but you only have a Thunderbolt connection port on your Mac, you can use a Firewire to Thunderbolt adapter cable to connect it to your Mac although transfer speeds will be at Firewire speed, not Thunderbolt speed.
The conclusion from all this is that in 2019, the fastest, most widely used and economical external hard drive connection that Mac users should focus on is USB 3.0.
All external drives use at least a USB 3.0 connection but many now support the faster Thunderbolt ports as well.
To summarize the speed difference between the different connections check the comparison table below which is done in order of speed.
Speeds are measured in Megabits per second (Mbps) and faster devices such as USB 3.0 and Thunderbolt in Gigabits per second (Gbps).
Note that these are maximum speeds and real world speeds may be 10-20% less depending on the type of data being transferred and other factors.
As mentioned earlier, there are no external drives that can achieve these speeds yet and the best you can expect is around 100-200 Mbps transfer speed from most mechanical drives and about double that from an SSD drive.
|Firewire 400||400 Mbps|
|USB 2.0||480 Mbps|
|Firewire 800||800 Mbps|
|USB 3.0||5 Gbps|
|USB 3.1||10 Gbps|
|Thunderbolt 1||10 Gbps|
|Thunderbolt 2||20 Gbps|
|Thunderbolt 3||40 Gbps|
The world of connection ports is changing rapidly and there’s an ongoing debate over which will eventually win out between USB 3.1 and Thunderbolt / USB-C.
At the moment though, it’s USB 3.0 that’s out in front.
For more on using USB 3.0 on Mac, check out Apple’s USB 3.0 FAQ.
You can format an external hard drive so that it works on both Mac and PC or Mac only.
The best models are ready formatted for use on Mac.
However, you can easily format any external hard drive on your Mac to work with both Mac and PC or Mac only. If you want to use the drive with both a Mac and PC it must be formatted in exFat or FAT32 format.
The problem is that FAT32 is limited to 4GB so for drives of 1TB or more, you have to use exFat.
If the drive you buy isn’t formatted for Mac and Time Machine you can find easy to follow instructions here.
Mac Backup Software
This could be an article in itself but we have absolutely no problem using Apple’s Time Machine software for backing up Macs and strongly recommend using it.
Time Machine is free in macOS, it’s quick and it’s easy to use. If anything happens to your hard drive, everything on your Mac including setup and configuration is saved in Time Machine.
Just plug Time Machine in case of data loss, operating system problems or plug it into a new Mac if your hard drive failed, and you can instantly roll back to the last working version of your Mac with all your files and folder.
Most external hard drive manufacturers also include their own backup and management software but they can be un-intuitive, inflexible and you really don’t need them.
Seagate’s Dashboard software for example is quite bloated and doesn’t make it easy to customize backups.
We hope you’ve found this guide to buying an external hard drive on Mac useful but if you have any questions, let us know in the comments below.