Ask GadgetGuy: what’s the difference between HDD and SSD?

To most people, the terms “HDD” and “SSD” are just three-letter acronyms, itself an initialism (TLA) that you can use like jargon. But what do these terms really mean for you, and which one delivers better results?

If you’ve ever looked for a computer, you’ve probably seen a few acronyms, initialisms, and names, brands and words that don’t really make much sense. In fact, so many of them exist that at times, it feels like you need a degree to make sense of them.

Two of these are being highlighted quite regularly, though, and that’s because we’re at an interesting crossroads where one technology starts to make tracks over the other, as solid-state drives starts to take over conventional hard disk drives in terms of use inside computers.

So what’s the difference?

SSD on the left, HDD on the right
SSD on the left, HDD on the right

Above we have two drives made by the same company, with a Samsung 2.5 inch hard disk drive and a Samsung 2.5 inch solid state drive.

You’ve probably heard those terms before, but if you haven’t or you need a refresher, essentially what you’re seeing is old versus new technology.

The old technology is the hard disk drive or “HDD”, a storage device that you can easily recognise thanks to the metal rotation platter usually found on the bottom of the drive which works in conjunction with a disk head to read and write information to the drive.

This is old school technology, and is generally the less expensive of the storage technologies out there. They’ve been in laptops and desktops for ages, and are the most common type of drive found in an external storage solution, such as a desktop or notebook drive, or even a network attach storage device (NAS) used for backing up your files.

But while their age might be a problem to some, it’s really the weight, the speed, and the power consumption that makes this older technology less desirable for our technologically friendly future.


Instead, solid-state drives will become that replacement solution, and when you see the term “SSD” in a spec sheet, the computer manufacturer is relying on a faster hard drive technology that offers less weight, speedier guts, no moving parts, and better battery life.

Those four points are the primary reasons to consider solid-state over conventional hard drives, because without moving parts, a solid-state drive is lighter, is less power hungry, and is generally much, much faster to run files from.

These drives obviously don’t rely on the same technologies as regular drives, and instead have appears like memory inside them, small bits of silicon that store files when communicated and powered through a storage controller in a fashion not so dissimilar from a thumb drive or a memory card.

Another technology that has a lot in common with solid-state is flash memory technology, which is essentially what is inside a solid-state drive.

Generally, solid-state and flash technology are one in the same, but whereas a solid-state drive connects to a computer with the same connections as a hard drive, flash storage can be plugged directly into the computer’s mainboard instead of at the hard drive level, not just allowing you to have the storage be fitted into place, but also minimising the amount of wires, if requiring any at all.

That makes flash and solid-state storage the better technologies to have in a mobile computer, because they’re faster, lighter, and better on batteries, which doesn’t matter as much with a desktop, but is a pretty solid reason to opt for them in a portable.

Solid-state drives like the one on the left offer the same connections as a hard drive, but have faster insides than their HDD siblings.
Solid-state drives like the one on the left offer the same connections as a hard drive, but have faster insides than their HDD siblings.

All machines — desktops included — prefer SSDs and flash media because they are much, much faster storage options, and while larger hard drives are generally preferable in bigger machines, the combination of technologies can be most helpful.

As such, you can find hybrid drives which take the massive storage from a conventional hard drive — HDD technology — and blend it with the flash media found inside solid-state storage — SSD — to create hybrids that move commonly accessed files to the solid-state section for faster access without needing to rely on a full solid-state drive, which would bring the cost up because it’s a more expensive technology.

Apple’s Fusion drive technology is one such example, which relies on a 128GB solid-state drive paired with a 1 or 3TB drive to do just that, providing a solid-state haven to move files to for easy access in a fast and timely manner.

Conventional external drives rely on conventional hard disk drives.


In the desktop world, that sort of speed is useful, as is keeping a larger disk storage size, because you want as much space as you can possibly can for as many files as you can make or download.

In fact, you can still find HDDs inside laptops and desktops today, and they’re much, much more cost effective, a point proven when you see that a 1TB solid-state drive can cost over $500 (and as much as $999!) while a 1TB notebook hard disk drive fetches a tag closer to $100. That’s five times the difference.

Essentially, if you need lots of storage, hard drives with moving parts offer it up in spades, with 4 and 6TB drives for desktop computers or external storage solutions for between $200 and $400, storage amounts that would cost a fortune right now if they were offered in solid-state flash-based drives.

Solid-state external drives offer solid-state flash storage inside a casing. It’s like having the speed of an SSD on the outside of your computer.


At one point, that will change, and solid-state will overtake completely, as it’s even beginning to show up in the world of external drives, beating its hard drive competitors in size and weight while costing a lot more in the process.

But if a laptop is where you’re going to be, and a mobile machine is what you’re using, with battery life being key, you’ll want to consider something with solid-state or flash inside, as it will just end up performing better overall, not just for the drive, but for the computer as a whole.

What’s inside a solid-state solution? Samsung’s external SSD, the T1, reveals solid-state storage, a controller, and the connections to a computer through a USB port. Oh and plastic. Can’t have a drive without plastic.