So, you’re finally tired of your computer throwing warning messages at you that your hard drive is full and you’re ready to upgrade. A quick search on Google for the latest hard drives, and now you’re even more confused.

NVMe? M.2? SATA? PCIe?

While this all seems a little alien to most people, let me break it down for you so you can make the best decision possible on your next hard drive purchase. Let’s start with the basics and work our way up. Keep in mind that this will be a fairly general breakdown of each. You can find a ton of more in-depth articles or videos online if you really want to dig into the specifics with these various hard drives.

Mechanical Drives

Starting from the bottom up, mechanical drives are pretty much old-school technology at this point. Sure, they’re cheap, but they also have a host of other problems that should dissuade you. Essentially, this is just your typical storage device that uses moving parts, like an optical disc, instead of being non-mechanical like an SSD.

So why are they inferior? Well, for starters, the moving parts in a drive like this use more power, generate more heat and are much, much slower than even the lower-end SSDs. If you are really on a budget however, I would suggest at least getting a 7,200 (or 10k) RPM drive for faster speeds.

SATA/M.2

So, moving on from the dinosaurs, this next section will cover what SATA means and what an M.2 drive is. While we’re on the subject, there are also 2.5-inch SSDs that will usually fit into the same spot as your old mechanical drive. These can be a good option for larger computers, but it’s best to jump straight to M.2 if you’re in the market for laptop hardware. If you’ve got a larger tower PC, then going the 2.5-inch route can be cheaper while warranting the same speeds (unless we’re comparing PCIe/NVMe, but we’ll get to that).

Over the last several years, SSDs have truly been a massive breakthrough for PC hardware. The transfer speeds of these drives are vastly superior to the old mechanical drives, giving you faster read/write speeds, boot and shut down speeds, loading times for games, video or pictures and more.

So how do they work? Well, it’s pretty simple.

Much like your thumb drive or USB stick, there are no moving parts to an SSD. Instead of a magnetic/optical disc, data is contained in microchips and because of this, the SSD is much faster.

Now that we’ve got the basics of an SSD out of the way, here’s where the SATA term comes into play. SATA (or Serial ATA) is your typical hardware interface for connecting hard drives or SSDs and also CD drives. Released way back in 2001, SATA has evolved considerably, though it is still slower than an M.2 drive.

A quick real-world comparison between a modern SATA III drive and M.2 can be seen in the throughput. SATA III maxes out at about 600MB/s, while an NVMe-equipped M.2 can top out at 3,500MB/s — compare these to your old mechanical drive (7,200 RPM) at 100MB/s. With that said, there’s an important point to note here. While M.2 drives can be smaller than SATA (not necessarily faster), not all of them are NVMe … now let’s dig into that.

NVMe/PCIe

Alright, you’ve made it to the motherland of hard drive nirvana — NVMe. SSDs are much faster than mechanical, but they are still throttled by the old SATA III connections they mostly use. This is where NVMe (Non-Volatile Memory Express) comes in. What this newer technology allows is the SSD to plug into a PCIe interface, which is much faster.

All NVMe means essentially is that you’re using a different bus for the component to communicate with your computer — what it’s not is a completely new type of memory. This is also why these drives can either be M.2 or PCIe (or Peripheral Component Interconnect Express).

Now while these hard drives sound like the perfect option (and they are nice), they also come with a premium — often hundreds more than their slightly slower cousins. So how do you decide which one of these is best for you? Well that depends on what you wanna do with your drives/PC.

If your budget is unlimited, by all means, go for the NVMe. Whatever you end up deciding on, keep in mind the price difference compared to the real-world translation in speed (or other factors). Often you’ll find that the top-of-the-line hard drives seem really cool and fast, but the price difference for them may not make sense for most people who are just gaming or occasionally doing some video or photo editing. If you are doing something hard-drive intensive, then the NVMe could be a nice upgrade.

Here’s an nice video on the topic that explains things even more. It’s a little older, but the tech remains mostly the same.