What’s the Diff: SSD vs. NVMe vs. M.2 Drives

What's the Diff? M.2 vs. NVMe vs. SSD

Storage technology has certainly changed over time, with new storage mediums taking aim at what’s become the industry standard: the hard disk drive (HDD). Of all the challengers, solid state drives (SSDs) are the most widely-adopted and likely to take the top spot—they’re fast, quiet, and retain information when they’re powered off (so you can just pop open your laptop and get back in the groove). 

Yes, they’re more expensive than traditional hard disk drives, but there’s value in their much faster read/write speeds, and they’re arguably more reliable depending on your use case in the long term. Even with those benefits, that’s not to say HDDs are obsolete, just that there is good reason to upgrade to SSDs in many cases. The decision from the judges: These two contenders get to share the spotlight, and you get to decide which drive works best for your needs. 

Once you’ve made the decision to invest in an SSD, you’ll have to choose the form factor  and possibly the interface. In this post we’ll cover some basics about SSDs that should help you choose which type of SSD is best for you, including:

  • What is an SSD?
  • What is a SATA SSD?
  • What is an M.2 SSD?
  • What is an MSATA SSD?
  • What is an U.2 SSD?
  • What is an NVMe SSD?
  • Which SSD is right for you?

A Brief Introduction to SSDs

SSDs are storage devices that use NAND-based flash memory to store data. They are now standard issue for most computers, as is the case across Apple’s line of Macs. Unlike traditional hard disk drives (HDDs), which store data on spinning disks, SSDs have no moving parts, which makes them faster, more reliable, and less prone to mechanical failures.

SSDs have become so common mainly because they are faster in terms of read/write speeds versus hard drives. This means that they can access and transfer data much more quickly. This makes them an ideal choice for use in high-performance computers, servers, and other devices that require fast data access and transfer speeds. They also use less power and are available at different form factors, such as 2.5” and M.2, so they can be used in a range of devices. You can read more about the difference between SSDs and HDDs in this post.

One downside of SSDs is that they tend to be more expensive than HDDs, especially when it comes to larger storage capacities. However, as the cost of flash memory continues to decrease, SSDs are becoming more affordable and accessible for everyday consumers. Comparatively speaking, they also have a more limited write cycle. While you usually don’t run into this limitation as a typical computer user, if you’re constantly saving large files like you would if you’re working with media files, for instance, it’s something to consider. 

Additionally, it can be harder to tell when an SSD is failing (no spinning disks to whir furiously at you), which means you’ll want to make sure you’re effectively monitoring your drives and backing up.  

What Is a SATA SSD?

A Serial Advanced Technology Attachment (SATA) is the standard storage interface used in many computers. A SATA SSD is an SSD equipped with a SATA interface to connect the storage device to a computer’s motherboard. The SATA SSD comes in the standard 2.5 inch form factor and has both power and data (SATA) connectors. If you buy an SSD external drive to connect to your PC, there will most likely be a SATA SSD inside. 

Generally, the SATA SSD is the least expensive type of SSD, all other factors being equal. This makes a great choice to get an instant performance boost out of your HDD-based computer, or add an external drive that can read and write data more quickly.

One thing to know about external SSD drives is that they should not be disconnected from your computer and stored away for long periods of time. Anything over a year is too long, and as the drive gets older it needs to be plugged in even more often. If you do want to use your SSD for long-term archival storage and have it disconnected from your main devices (air gap, anyone?), then it’s a good idea to either store them with about 50% charge, or power on the SSD every few months to refresh the charge. 

An image of a Western Digital 1TB SATA SSD.

What Is an NVMe?

Non-Volatile Memory Express (NVMe) is a storage protocol that offers high-speed and efficient communication between a computer’s CPU and SSDs. Drives that use NVMe were introduced in 2013 to attach to the Peripheral Component Interconnect Express (PCIe) slot directly on a motherboard instead of using the traditional SATA interface typically used by HDDs and older SSDs. Unlike SATA, which was originally designed for slower HDDs, NVMe takes advantage of the low-latency and high-speed capabilities of SSDs. NVMe drives can usually deliver a sustained read-write speed of 4.0 GB/s in contrast with SATA SSDs that limit at 600 MB/s. Since NVMe SSDs can reach higher speeds and handle multiple data transfers simultaneously, it makes them ideal for gaming, high-resolution video editing, and applications that require high-performance storage, such as enterprise databases, virtualization, and data analytics.

Their high speeds come at a high cost, however: NVMe drives are some of the more expensive drives on the market.

An image of a Kioxia NVMe SSD.

To sum up our analysis on storage protocols in SSDs, here’s a handy chart:

InterfaceSerial Advancement Technology Attachment Non-Volatile Memory Express
BusSATA busPCIe bus
Data Transfer SpeedsSlower (up to 600 MB/s)Faster (typically 3000 MB/s and up to 7,500 MB/s)

What Are M.2 Drives?

M.2 drives, also known as Next Generation Form Factor (NGFF) drives, are a type of SSD that uses the M.2 interface to connect directly into a computer’s motherboard without the need for cables. M.2 is a form factor, which refers to the standard size of a component. So, while we’re comparing NVMe to SATA in storage protocol above, a direct comparison for the M.2 SSD is a traditional, 2.5 inch SSD. 

M.2 SSDs are significantly smaller than traditional, 2.5 inch SSDs. Because they can use either SATA or NVMe to connect to the motherboard, they have the potential to be much faster when they’re utilizing the latter. They’re also more power-efficient than other types of SSDs, which improves battery life in portable devices. Because they take up less space while delivering all of the above, M.2 drives have become popular in gaming setups. (Game on, friends.)

Even at this smaller size, M.2 SSDs are able to hold as much data as other SSDs, ranging up to 8TB in storage size. But, while they can hold just as much data and are generally faster than other SSDs, they also come at a higher cost. As the old adage goes, you can only have two of the following things: cheap, fast, or good.

M.2 drives are easy to install, and they can be added to most modern motherboards that have an M.2 slot. If your motherboard does not have an M.2 slot, you may be able to use an M.2 drive by using an adapter card that fits into a PCIe slot. So, before you run out and buy an M.2 SSD, you’ll need to know which interface your computer will accept, M.2 SATA or M.2 PCIe.

A Samsung SATA M.2 SSD.

What Are mSATA Drives?

mSATA, or mini-SATA, is basically a smaller version of the full-size SATA SSD that is designed for smaller form factor systems where space is limited. The mSATA form factor is compact like M.2, but they are not interchangeable. Currently, mSATA drives only support the SATA interface.

A Rogob mSATA SSD.

What Are U.2 Drives?

U.2 drives look like a 2.5” drive but are a bit thicker, and they use a different connector that sends data through a PCIe interface. The U.2 SSD was developed to enable the newer and faster NVMe-based PCIe SSDs to plug into the same drive backplane as older SAS and SATA drives. This allows the drives to be hot-swappable, an especially useful feature in enterprise server and storage systems.

A Mircon U.2 SSD.

Which SSD Is Best to Use?

There are a few factors to consider in choosing which drive is best for you. As you compare the different components of your build, consider your technical constraints, budget, capacity needs, and speed priority.

Technical Constraints

Check the capability of your system before choosing a drive, as some older devices don’t have the components needed for NVMe connections. Also, check that you have enough PCIe connections to support multiple PCIe devices. Not enough lanes, or only specific lanes, means you may have to choose a different drive or that only one of your lanes will be able to connect to the NVMe drive at full speed.

The same advice holds if you’re adding an SSD to your NAS array. Most newer models will be compatible with adding an SSD, but you should always double check your NAS specs before you commit to a purchase. And remember: even though SSDs offer many benefits, especially when you’re looking to add caching or using your NAS for media workflows, there are several use cases where you’d see minimal advantage compared with an HDD, such as if you want a NAS to store large amounts of infrequently accessed files (i.e. in backup/archive scenarios).


If you plan to be making a lot of large file transfers or want to have the highest speeds for gaming, then an NVMe SSD is what you want. Until recently SATA SSDs were much more affordable options compared with NVMe drives, but that is changing rapidly. For example, at the time of publication, a Samsung 1TB SATA SSD (870 EVO) retails for $990 on Amazon, while a Samsung 1TB NVMe drive (970 EVO) is listed for $150only $98 on sale on Amazon. That said, those 8TB NVMe drives we talked about are running about $850+, depending on the manufacturer. 

Drive Capacity

SATA drives usually range from 500GB to 16TB in storage capacity. Most M.2 drives top out at 2TB, although some may be available at 4TB and 8TB models at much higher prices.

Drive Speed

When choosing the right drive for your setup, remember that SATA M.2 drives and 2.5 inch SSDs provide the same level of speed, so to gain a performance increase, you will have to opt for the NVMe-connected drives. While NVMe SSDs are going to be much faster than SATA drives, you may also need to upgrade your processor to keep up or you may experience worse performance. Finally, remember to check read and write speeds on a drive as some earlier generations of NVMe drives can have different speeds.

Whatever You Choose, Back It Up

Before choosing a new drive, remember to back up all of your data. Backing up is essential as every drive will eventually fail and need to be replaced. The basis of a solid backup plan requires three copies of your data: one on your device, one backup saved locally, and one stored off-site. Storing a copy of your data in the cloud ensures that you’re able to retrieve it if any data loss occurs on your device.

Interested in learning more about other drive types or best ways to optimize your setup? Let us know in the comments below.

FAQs about NVMe vs. M.2 drives

What is the difference between NVMe and M.2 drives?

NVMe and M.2 are often used interchangeably, but they refer to different aspects of storage technology. Non-Volatile Memory Express (NVMe) drives attach to the Peripheral Component Interconnect Express (PCIe) slot directly on a motherboard instead of using the traditional SATA interface, resulting in higher data transfer speeds. M.2, on the other hand, is a physical form factor or connector used for SSDs. M.2 drives can support various storage interfaces, including NVMe, SATA, and others, providing flexibility in terms of compatibility and speed.

Which is faster, NVMe or M.2 drives?

NVMe and M.2 drives are not directly comparable in terms of speed because they refer to different aspects of storage technology. NVMe (Non-Volatile Memory Express) is a storage protocol that provides high-speed communication between the computer’s CPU and SSDs. It is designed to take full advantage of the capabilities of SSDs and can offer significantly faster data transfer speeds compared to traditional interfaces like SATA.

M.2, on the other hand, refers to a physical form factor or connector used for storage devices, including SSDs. M.2 drives can support various interfaces, including NVMe, SATA, and others. The speed of an M.2 drive depends on the specific interface it uses. NVMe M.2 drives, which utilize the NVMe protocol, can provide faster speeds compared to M.2 drives that use the SATA interface.

In summary, NVMe is a storage protocol that can be implemented in various form factors, including M.2, and NVMe drives tend to offer faster speeds compared to M.2 drives that utilize the SATA interface.

Can NVMe be used in any M.2 slot?

NVMe drives can generally be used in M.2 slots, but it is important to ensure compatibility with the specific M.2 slot on your motherboard. M.2 slots can support different types of interfaces, including SATA and NVMe.

What are the advantages of NVMe in M.2 drives?

NVMe (Non-Volatile Memory Express) is a storage protocol that can be implemented through various form factors, one of which is M.2.

The main advantage of NVMe technology is its high-speed data transfer capabilities. Compared to traditional storage interfaces like SATA, NVMe provides significantly faster performance. It leverages the Peripheral Component Interconnect Express (PCIe) interface, allowing for direct communication between the CPU and the SSD. This results in reduced latency and improved overall system responsiveness.

M.2, on the other hand, is a physical form factor or connector that can support various interfaces, including SATA and NVMe. M.2 drives can accommodate NVMe SSDs, allowing them to take advantage of the faster speeds provided by the NVMe protocol. In addition to the ability to utilize a faster NVMe protocol, the advantages of an M.2 size are its small size and easy direct-to-motherboard installation.

Are NVMe drives more expensive than SATA drives?

Until recently SATA SSDs were much more affordable options compared with NVMe drives, but that is changing rapidly. For example, as of June 2023, a Samsung 1TB SATA SSD (870 EVO) retails for $90 on Amazon, while a Samsung 1TB NVMe drive (970 EVO) is listed for only $98 on sale on Amazon. Prices are now comparable.


About Andy Klein

Andy Klein is the Principal Cloud Storage Storyteller at Backblaze. He has over 25 years of experience in technology marketing and during that time, he has shared his expertise in cloud storage and computer security at events, symposiums, and panels at RSA, SNIA SDC, MIT, the Federal Trade Commission, and hundreds more. He currently writes and rants about drive stats, Storage Pods, cloud storage, and more.