I’ve been regularly buying hard disk drives for the best part of three decades. Over this time, the capacities have increased tremendously. It’s sometimes difficult to appreciate just how much hard disk capacities have increased over this time. Whilst many data-hoarders are well aware of current drive capacities, there’s still some confusion from the uninitiated. I often receive comments on this blog, and on forums asking for advice about which hard drive to choose and which capacity to go for.
I thought I’d write this post to break down the meaning of hard disk drive capacities, to list the current common capacities, and perhaps make some suggestions on which hard drive you might need, depending on the intended use.
The meaning of MB, GB, TB
When we see hard disk drives advertised, they’ll often have their capacities listed in MB (not so much nowadays!), GB, or TB. Each of these are abbreviations, intended to convey a measure of the disk’s capacity (i.e. how much data the hard drive can store).
MB is short for Megabytes. Basically, one megabyte is one million bytes. It may sound a lot, and many moons ago, it was indeed quite a lot. Nowadays, it’s a minuscule amount, in the grand scheme of things. You’ll never see a new hard drive being sold with a capacity listed in megabytes. In the 1990’s you might have seen hard drives being sold with capacities advertised as 600MB or 750MB, but those days are sadly long gone.
GB is the abbreviation for Gigabytes. One gigabyte is one billion bytes or one thousand megabytes. Again, not too long ago, a hard drive advertised as having a capacity of several gigabytes would have been well regarded. Today, a gigabyte is a relatively small amount of data when looking at the bigger picture.
The abbreviation for Terrabyte is TB. If you’ve been following along, you can probably guess that one terabyte represents one thousand gigabytes, or to put in plainly one trillion bytes!
The capacities of most modern hard disk drives are today measured in terabytes. If you’re looking to purchase a hard drive for the first time, you can probably disregard the above explanations of MB and GB and just focus on the headline “TB” figure.
List of common hard disk storage capacities
Below is a list of the current, commonly available hard disk storage capacities. There’s a brief explanation of what each capacity might be suitable for. If you already have a hard drive capacity in mind, then skip down the list to find it, and see if it meets your requirements or expectations.
A 128GB hard drive is very small by today’s standards. You’ll still find hard disks with a capacity of 128GB on sale, but they’ll generally be SSD (Solid State Drives), intended for replacing a failed drive in an older system.
At the very bottom end of the PC market, you’ll occasionally find pre-built PC desktops or laptops that ship with a 128GB SSD as their system/operating system drive. Sometimes the manufacturer will supplement this with a larger, secondary hard disk drive but with budget systems, the 128GB drive will be all the storage that’s included with the system.
For reference, the latest version of Microsoft Windows (Windows 11), requires a minimum hard disk capacity of 64GB. This means that Windows 11 could quite easily be installed on a 128GB disk, but it’ll be taking up a huge proportion (50%) of the disk’s capacity. This means there’ll be hardly any free capacity left for things like photos, applications, videos, etc. For this reason, you should avoid hard disks with a capacity of 128GB if possible.
As with 128GB drives, new 256GB drives nowadays tend to be exclusively solid-state (SSD). You won’t find any manufacturer still making the traditional 256GB mechanical, rotational hard disk drives. A hard drive with a capacity of 256GB is very much at the bottom end of the market today. Some budget systems will still ship with a 256GB disk but if you buy one of these you’ll probably need to buy an additional larger drive as you’ll find it just isn’t sufficient.
As of 2022, 512GB hard drives are the smallest capacity traditional hard drives that are still being manufactured and readily available. 512GB (or half a terabyte, as they’re often called) drives are in a strange position at the moment. They’re really too small for any modern application, yet are large enough that there’s still a demand from certain segments. New 512GB drives are generally bought to replace failed hard drives in legacy systems that aren’t capable of supporting a higher capacity drive. Many industrial devices (e.g. CNC Machines) have built-in hard drives with a capacity of 512GB and when they fail, they need to be replaced with something similar. 512GB drives often cost as much, if not more than larger (i.e. 1TB) drives, and for this reason, I certainly wouldn’t recommend you buy a drive with this capacity for general use in 2022.
Hard drives with less than 1TB storage capacity aren’t really suitable for most people, in this day and age. Storage requirements have increased exponentially over the years and most people in the know would only consider buying a new drive with at least 1TB capacity.
Whilst 1TB hard drives aren’t considered huge, they are more than adequate for lightweight or causal users and their relatively low price point still makes them attractive to many.
To put into context how much 1TB of data is, a 1TB hard disk drive could store either:
- 1500 uncompressed audio CDs
- 125,000 uncompressed/RAW photos (at 4.2 megapixels, 16-bit depth each)
A 1TB hard drive is likely suitable if you fall into one of these categories:
Lightweight Home PC User, Admin/Office Worker
It should go without saying that a 2TB hard disk drive has twice the storage capacity of a 1TB drive. It would be reasonable to expect that they cost twice what a 1TB drive does. This isn’t the case, however. The cost difference between a 1TB and a 2TB drive is small.
Many manufacturers of pre-built PC systems may install a 1TB drive rather than a 2TB drive. This is because they’re trying to save every penny and they know 1TB of storage is enough for most users. When buying a new hard drive for yourself, however, it often makes sense to choose a higher capacity because you’re unlikely to feel the price difference.
At the time of writing, one of the larger IT retailers in the UK (eBuyer) are selling 1TB drives for £26, before tax. They’re also offering 2TB drives for just £36. The 2TB drives not only have twice the storage capacity, but they are also faster and offer four times the amount of cache (256MB vs 64MB). Clearly, the 2TB drives represent better value for money.
If you fall into one of these categories, a 2TB might suit you:
Average Home PC User, Student, Lightweight Home PC User wanting to “future-proof” for a while.
4TB is a respectable amount of storage in any modern-day system. The higher-end (i.e. expensive!) gaming PCs on the market usually ship with a 4TB hard drive installed. At the time of writing (2022), 4TB drives are available from major UK retailers for around £65 + tax.
If you’re looking to replace an existing hard drive that has failed, adding a secondary hard drive or perhaps even building a new PC, a 4TB drive is a good choice. At the moment, it strikes the right balance between cost and “future-proofing”. Whilst some argue that there’s no such thing as “future-proofing”, it’s difficult to argue with the fact that it’s going to take longer to consume 4TB of space than it would 2TB or even 1TB!
4TB should be sufficient for these classes of user:
PC “Power Users”, PC Enthusiasts, PC Gamers, Amateur Photographers.
To put into context how much data you could store on a 4TB disk drive, it can potentially hold either:
- 40 uncompressed UHD 4K movies (i.e. movies backed up from 100GB blu-ray discs)
- 50 “AAA Rated” PC games (based on an average game size of 75GB)
8TB hard drives are still quite rare, especially in the consumer space. If you’ve no idea what size hard drive you need, it’s unlikely that you need one with this much storage capacity. The types of users needing 8TB of storage are usually acutely aware that their activities or industry needs such a vast amount of storage space.
As of 2022, you generally won’t find any pre-built PC system shipping with 8TB of storage as standard. This is true even when looking at top-tier gaming PCs and CAD workstations. At the point when most users find they need 8TB of storage, there are usually more optimal solutions, such as investing in a server or a NAS device.
With that said, there’s no real premium to pay for an 8TB hard disk drive. They cost around twice as much as a 4TB drive, so if you’ve got the budget and want to make sure you don’t need to replace your hard drive for the foreseeable future, there’s no real reason not to upgrade to an 8TB disk today.
The following users would likely benefit from a large 8TB hard drive:
PC Enthusiasts, Professional Photographers, Videographers / Youtubers, Professional Gamers.
16TB drives are currently the highest capacity drives that are generally available to the general public. 16TB drives are currently so rare that it’s unusual for them to be installed into a desktop PC. The majority of 16TB disks will find themselves in servers or NAS devices.
Whilst it’s possible to install a 16TB drive in your PC, there are some considerations before doing so. The main question when dealing with such a large amount of storage is “how will it be backed up?”. 16TB is too much for most users to be uploading/syncing to the cloud on a regular basis. This means you’ll likely need to copy the data to a secondary external USB hard drive. This is no mean feat when we’re dealing with 16TB of data. It’s going to take a significant amount of time to copy 16TB over USB.
If you really need 16TB of storage space, I would recommend buying a NAS device or similar. It’s just going to make backing up and sharing your data so much easier.
Users who may need 16TB of storage:
Business Users, Data-hoarders, Professional Videographers / those working in TV and film production.
Hard disk storage capacities have been increasing at an exponential rate for some time. In this post, we’ve listed the commonly available storage capacities of current hard disks. Whether you’re looking to purchase a new pre-built PC or to add additional storage to your existing PC, hopefully, you’ll have a clearer understanding of what you need.
For most people, I would recommend a 4TB hard drive, as at the moment, this is the sweet spot for capacity vs cost. If you’re a professional or enthusiast then there are plenty of other options, including larger capacity drives as well as servers and NAS devices.
Regardless of which capacity hard disk you chose, it’s important to have a plan in place regarding backing up your precious data. The larger the hard drive you choose, sadly, the more data you stand to lose should the drive fail. Eventually, all hard drives fail so it’s wise to put a backup strategy in place before it’s too late.
This post was published in 2022 but I’ll try to keep it updated as hard disk storage capacities inevitably increase. If you’ve any questions or notice anything I’ve missed then please leave a comment. Happy data-hoarding people!