As the prices of NVMe SSDs fall every day, we don't see much difference in cost between the best NVMe SSDs and their SATA-based equivalents. When the cheapest 2.5-inch 1 TB SATA SSD is only $24 less than an equivalent capacity NVMe PCIe drive (and four times slower), why bother with older SATA technology when you can move into the future for so cheap?

Where SATA's theoretical performance limit is 600 MB/s, and PCIe 3.0's is 4,000 MB/s, PCIe 4.0 SSDs can double that figure to a maximum of 8,000 MB/s. The current top speed of available Gen 4 drives is around 7,000 MB/s, which is double that of the previous generation.

PCIe 5.0 SSDs can exceed 10,000 MB/s and onwards up to their theoretical limit of around 16,000 MB/s. They used to be hot and too expensive for what they offered, but the new generation of PCIe 5.0 drives so much better, they're much easier to recommend now.

The M.2 socket has been included on motherboards of all kinds for many years now, so the chances are that there's a spare slot sitting inside your existing gaming PC. Check out your motherboard's specs page online before pulling the trigger on an NVMe SSD purchase, though, to be sure.

Those harboring a board that's a few years old now, do yourself a favor and make sure it supports booting from an NVMe drive first. Not all older motherboards do, especially if you're going back multiple CPU generations (maybe a full upgrade is due, if so).

If you don't have any NVMe slots, you can buy expansion add-in cards that will offer one or more NVMe slots in exchange for one of your PCIe slots on your motherboard, just be aware that these are at an added cost and take up precious room.

Yes, you can. The M.2 socket is identical between the two generations of interface, and so a PCIe 5.0 SSD will fit comfortably inside a PCIe 4.0 slot. They will also function perfectly well, except the Gen5 drive will be limited by the speed of the older interface.

The same goes for dropping a PCIe 5.0 into a PCIe 3.0 socket. You're just wasting the potential of the higher-speed drive by dropping it into a slower slot, is all, but it will work.

Right now, PCIe 4.0 is the go-to PCIe generation. That's because it offers high speed at a reasonable cost. However, the newest PCIe 5.0 gaming SSDs on the market offer up to double the sequential read/write performance, as well as outstanding random 4K, all without getting blisteringly hot. Gen 5 drives are still more expensive than Gen 4 ones, though.

Here are the rough speeds (multiply by 1,000 to get MB/s) for each PCIe generation over x4 lanes:

PCIe 1.0 / Gen1: 1 GB/s
PCIe 2.0 / Gen2: 2 GB/s
PCIe 3.0 / Gen3: 4 GB/s
PCIe 4.0 / Gen4: 8 GB/s
PCIe 5.0 / Gen5: 16 GB/s

The easy answer is: as big as you can afford. With SSDs, the higher capacity, often the quicker they are. That's because you end up with more memory dies plumbed into a multi-channel memory controller, and that extra parallelism leads to higher performance.

We would traditionally say that an entry-level SSD should be 1 TB in order to pack in your operating system, for slick general system speed, and your most regularly played games. But such is the increasing size of modern games that a 2 TB SSD is increasingly looking like the minimum recommendation, and a 4 TB drive or above will really give you some proper breathing room for lots of big game installs.