When it comes to hard drives, NVMe has shaken things up in dramatic fashion. Standard SATA SSDs aren’t a big deal anymore, especially not among enthusiasts looking to get as much speed as possible from their machines. In fact, they’re not even considered when maximum performance is concerned. So why has NVMe stolen all the thunder? Is a NVMe drive really necessary? To get to the answer, you’ll first need to step back and understand a bit about SATA and NVMe.
What Is SATA?
Back in the 90’s computers were filled with these big flat gray cables. They were obnoxious, ugly, and blocked all the airflow in the case. To make matters worse, they were really slow. These were ATA cables, sometimes called Parallel ATA or PATA.
When the year 2000 rolled around, a solution to the ugly gray ribbon problem arrived in the form of SATA, or Serial ATA. It was much faster, and the cables weren’t a huge nuisance. In the years since, SATA has undergone a few revisions, and through versions 2.0 and 3.0 have gotten much faster. When you talk about SATA drives now, you’re talking about SATA 3 – 3.3 to be specific.
SATA’s speed boost not only allowed for disk-based hard drives to get much faster, it paved the way for solid state to revolutionize hard drive speed.
What Is NVMe?
Not every connector on your computer’s motherboard is equal. Some are built to handle a ton more data than others. Believe it or not, the SATA connectors on motherboards are fairly low on the list of data bandwidth.
PCIe ports, on the other hand, are built for maximum speed and data by the truckload. They’re meant to handle all the calculations coming from devices like graphics cards. What if you could connect your hard drive through PCIe? That’s exactly what NVMe is.
Before any confusion, there are PCIe drives that aren’t NVMe drives. NVMe stands for Non-Volatile Memory Express. Essentially, NVMe uses the same kind of memory as RAM, but it isn’t erased every time your computer powers off. As a result, NVMe only makes sense over PCIe, and the speed offered by PCIe can only be fully taken advantage of by NVMe, making the two almost synonymous.
NVMe uses the extremely high data bandwidth of PCIe to plug the SSD as directly into the motherboard as possible, boosting speeds to levels SATA could never achieve.
The Difference in Speed
So NVMe is faster, but just how much faster is it really? There’s a simple way to estimate that.
SATA 3’s theoretical data transfer speed is 6Gb/s. Practical circumstances are a bit different, and the actual max works out to around 600MB/s. When you consider what most Internet speeds are, that’s actually very fast.
Now we’ll take a look at PCIe. PCIe slots are split into lanes in multiples of 4. Usually, you’ll find 4-, 8-, and 16-lane slots on a motherboard. The 16-lane slots are the ones you usually plug graphics cards into. For PCIe 3.0, the current standard, each lane has a theoretical speed of 1GB/s. So a 16-lane slot has a possible limit of 16GB/s. It’s much more common to see 4- and 8-lane cards in the consumer market, but the potential is undeniable.
To take things a bit further, you can look at the reported read and write speeds of actual drives. Most SATA SSDs report read and write speeds around 550MB/s, right in line with the SATA 3 cap. NVMe drives, in contrast, go up to around 3GB/s read and 1.5-2GB/s write, and that’s on a 4-lane M.2 interface. The difference is startling.
What to Choose and When
You’re not going to load your motherboard up with NVMe drives in every slot, and unless you have substantial disposable income, you probably won’t be using 1TB NVMe drives. They’re best-suited for an operating system drive, with a larger SATA SSD backing them up for games and other larger files. Of course, traditional disk hard drives are still best for storage.
Most higher-end laptops and desktop motherboards have a built-in M.2 slot. M.2 is PCIe port-designed specifically for NVMe hard drives. It sits low and flat on your motherboard and leaves the other PCIe slots free for graphics cards and other add-on cards. It’s perfect for laptops as well, since it takes very little space.
Generally, you’ll want a 256GB or 512GB NVMe drive for your operating system. It’s the fastest possible drive, and it’ll speed up your OS and all the programs running on your system. For most people, that’ll be enough. SATA SSDs make an excellent supplement for that, adding space for games, programs, and files that you want to load quickly.