SSDs have quickly become the primary storage medium for all computers, housing the data that we use most often, like our OS and commonly used applications. Although the general quality of SSDs has improved across the board in the last decade, not all of them are created equal, and in fact, certain SSDs are actually a poor buy depending on your use case. That's why I always check these 5 SSD specs before I add one to my cart.

5 Interface

The difference between SATA and PCIe is significant

Beyond pure form factor considerations, the difference between an SSD that runs through SATA and one that runs through PCIe lanes is significant. If you don't have a free M.2 slot, you might be confined to using a SATA drive unless you feel like adding an expansion card, and in most scenarios, you'll end up with slower speeds. If you're simply using the drive for tasks that are light on writing or to spruce up an older system, a SATA SSD is completely fine. This will certainly be an obvious one to some more experienced builders, but the difference in the interfaces is a very important one to consider before buying an SSD.

4 Capacity

Obvious, but important to carefully consider

Enthusiasts know that capacity isn't something to dismiss when buying a new drive. It might sound like an obvious statement, but your SSD's capacity is important depending on what you intend to use it for. If it's your daily drive, and you consider yourself a power user, you might need upwards of a couple of terabytes. If you're using it to add some secondary game storage to your PC or handheld, the kinds of games and their space requirements are important to consider, but you could get away with a terabyte or less if you don't keep games installed for very long.

3 Speed

The specifics matter a lot here

With the more obvious stuff out of the way, we can enter the realm where things get more nuanced. SSD speed can look different depending on how you measure it. There's sequential read and write speeds, which refer to large, sustained file transfers, and then there's random read and write speeds, or IOPs. High random read and write speeds are felt most in things like your operating system, texture streaming in games, and some productivity apps. Both are important, but it does matter what sorts of tasks you'll be doing.

If you're buying an SSD to be your boot drive, you want something with great IOPs, whereas if you're frequently working with large amounts of data on a secondary drive, higher sequential speeds are way more important. It's unlikely a high-end SSD won't have decent speeds for both functions, but prioritizing one over the other based on your workload is how you'll get the most out of your new drive.

2 Durability

How long will it last?

While it's true that the vast majority of users will never have to worry about SSD longevity, if you're doing data-heavy work, I'm making sure I buy an SSD that has the best chance of being in it for the long haul. For something like a scratch disk, or frequent VM usage, heavy write cycles are put on the drive. TBW is the main spec to look at, and it refers to terabytes written. The higher the number, the longer the drive can last. It might not matter to most people for everyday work, but when it does matter, it matters a lot.

1 DRAM cache

The mere presence of one alone can make a huge difference

Besides drive endurance, nothing else matters as much to real-world performance as the DRAM cache. It essentially allows your drive to be able to access the data it needs much faster, and enables even higher random read and write speeds. A DRAM-less SSD will feel quite slow running things like an OS or even writing large files. They're ok for breathing some life into an old system or doing any kind of heavy sequential reads, but should be avoided when you plan on doing essentially anything else.

The presence of one can be hard to check; many manufacturers don't make it obvious if a drive has a DRAM cache, so you might have to do some digging to find out. Check the manufacturer's product page, as the spec sheet on online stores usually leaves this information out for some reason.

Few things matter more than these 5 specs

An SSD can be the difference between a snappy experience and a slow one, and not all the specs are worth considering. When you go to buy a shiny new drive, whether it's to replace your primary storage or just add some more space for your growing game library, checking these 5 specs is paramount. If you're considering using SSDs for bulk storage in a NAS, however, there are some important factors that might make you rethink your approach.