It is normal to get confused while picking the right M.2 SSD. Getting a normal 2.5″ SATA is pretty easy because you always know there would be no problems related to the form factor.
But, the M.2 SATA and NVMe (Non-Volatile Memory Express) SSDs will look similar to each other and that’s where most people make mistakes. So, I am here to help you properly understand the differences and pick the right one for you.
M.2 SSD storage comes in two different types. The first one is M.2 SATA and the second is NVMe M.2. So, what is the difference between them both?
Well, the answer is pretty simple. The main difference is the compatibility and the speed. The M.2 NVMe SSDs are not compatible with the M.2 SATA ports.
There are various other differences which we are going to cover below in this article. So, lets get started.
What is M.2?
You see M.2 with both SATA and NVMe drives. So, what exactly is M.2. Well, it’s important to mention M.2 with these devices because it describes the form factor of the device. (Form Factor is basically the identification of the shape and size of any hardware device).
The maximum size you will see in M.2 form factor is 4.33 x 0.84 inches. That means whether it is NVMe M.2 or the SATA M.2, both of them will obey this form factor. That is why you will not see any M.2 SSD more than the size of 110 x 22 mm. However, the port configurations can vary. And, yes, these two different SSDs come in different port types. Let’s discuss it below.
Keep a thing in mind that not all M.2 ports are made only for NVMe. Some motherboards will have SATA-based M.2 ports however some will come with NVMe support. But, you should always beware of the ones that support PCIe but do not work with the NVMes.
How M.2 SATA SSD Looks Like?
All the M.2 SATA SSDs will have their form factor written on their body. But, you can also check the type of port before buying it. It will have two small pin connectors on both ends with a bigger connector at the center. Let’s look at the image below for a better understanding.
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In simple words, the SATA M.2 SSD will have two small cutout ports on both sides.
How NVMe M.2 SSD Looks Like?
This one will also have its form factor written on the body. But, you can easily tell the difference by looking at its connection type. So, NVMe M.2 SSD will have two separate connectors instead of three. One will be much bigger and the second one will be smaller. See the image below.
Difference between the specifications of both
The next big difference between these types of SSDs is the specifications. SATA M.2 and 2.5 inch SATA SSD have the same specifications called SATA.
However, the NVMe M.2 works on the PCIe bus and that’s why it offers more speed as compared to the SATA bus. The NVMe is the protocol here and M.2 is the form factor as we all know.
If we talk about the modern motherboards with SATA 3 bus, they can support the speed of 600 MB/s. But, PCI Express can work with a speed of up to 4000 MB/s.
According to Wikipedia, the latest PCIe 5.0 can reach a transfer speed of up to 8 GB/s on its x4 slot. However, the most available version i.e. PCIe 3.0 x4 is fast enough to provide you with a speed of up to 4 GB/s.
Normally, you get 7 to 8 times more speed in NVMe as compared to SATA.
So, now, you might have a clear idea of what are the specifications of both these SSDs and how they make a difference.
M.2 NVMe vs M.2 SATA SSD: What are the Differences?
1. Form Factor Difference
Both M.2 SATA and M.2 NVMe SSDs follow the same form factor. The sizes are same. But, there will always be a difference in the notch on its connector end. M.2 NVMe SSDs have a single notch on the right side, known as the ‘M’ key. M.2 SATA SSDs have two notches, known as the ‘B’ and ‘M’ keys.
| Form Factor | M.2 NVMe | M.2 SATA |
|---|---|---|
| Size | 22mm x 30-110mm | 22mm x 30-110mm |
| Shape | Rectangular | Rectangular |
| Notch | Single, ‘M’ key | Double, ‘B’ and ‘M’ keys |
2. Interface Difference
M.2 NVMe: The faster interface
M.2 NVMe SSDs use the Non-Volatile Memory Express (NVMe) protocol, but here’s the kicker: they operate over a PCIe (Peripheral Component Interconnect Express) bus. In layman’s terms, think of PCIe as a super-fast highway with multiple lanes that allows for more data to travel.
You’ll often see NVMe SSDs described with “PCIe Gen3 x4” or “PCIe Gen4 x4.” What does that mean?
- Gen3 or Gen4: This is the generation of the PCIe interface. Gen4 is newer and faster.
- x4: This indicates the number of lanes. More lanes = more speed.
| Interface | M.2 NVMe | M.2 SATA |
|---|---|---|
| Type | PCIe (NVMe protocol) | SATA III |
| Generations Available | PCIe 3.0, PCIe 4.0 | N/A |
| Lanes | Up to 4 (x4) | N/A |
M.2 SATA Interface: The Reliable One
On the flip side, M.2 SATA SSDs use the SATA III interface, which is the same as that of older, 2.5-inch SATA SSDs. It’s a tried and tested tech, but it doesn’t offer the blazing speed of PCIe. Don’t get me wrong, SATA III is not slow; it’s just not in the same league as NVMe when it comes to raw speed.
3. Speed Difference: NVMe SSDs are always faster
| Feature | M.2 NVMe Gen 5 | M.2 NVMe Gen 4 | M.2 NVMe Gen 3 | M.2 SATA |
|---|---|---|---|---|
| Max Read Speed | Up to 14,000 MB/s | Up to 7,000 MB/s | Up to 3,500 MB/s | Up to 600 MB/s |
| Max Write Speed | 8,000 MB/s | Up to 7,000 MB/s | Up to 3,300 MB/s | Up to 540 MB/s |
| PCIe Generation | PCIe 5.0 | PCIe 4.0 | PCIe 3.0 | N/A |
| Bandwidth Per Lane | 32 GT/s | 16 GT/s | 8 GT/s | N/A |
| Total Bandwidth (x4) | 128 GB/s | 64 Gbps | 32 Gbps | N/A |
Clearly, the M.2 NVMe is way faster than the M.2 SATA SSDs. So, there is nothing much to talk about here.
With the launch of the latest Gen 5.0 of PCIe, SSDs like Kingston T700 are reaching up to 11,700 MB/s of read speed.
Speed Comparison: SATA M.2 vs NVMe M.2
As we have discussed above, the SATA M.2 can have a maximum speed of up to 600 MB/s. This speed can’t be increased in any way. However, if your motherboard has SATA 2.0, the speed may decrease a bit.
But, the NVMe M.2 is going to give you much more speed as compared to the SATA M.2. This is because it works on PCI Express specifications as we have already discussed. So, yes, you can reach up to 8 GB/s with the latest version of PCIe in your system and a good NVMe SSD.
But, the PCIe v5.0 motherboards are very expensive. So, you will mostly see the support of PCIe 4.0 which is good enough. The speed of PCIe 3.0 x1 slot will be 1 GB/s. So, when we connect our NVMe SSD to M.2 NVMe PCIe 3.0 x4 slot, you will get a speed up to 4GB/s or 4000MB/s.
Its means, if you are buying an NVMe SSD with a read/write limit of 2000MB/s, you are going to get it for sure with your PCIe 3.0 x4 slot.
Price Comparison: SATA M.2 vs NVMe M.2
Price is never a barrier if you really want to enhance your system’s capabilities. But, buying any computer hardware can be pretty costly. So, we should know which one is affordable here. There is no need to see this comparison if you do not have the option to choose between both drives. If your motherboard doesn’t support PCIe, you will always have to buy SATA M.2.
NVMe M.2 drives can cost you 2x more as compared to the SATA M.2 drives. But, this price is worth it because of the fast working speed of NVMe drives.
You can easily buy a 1TB SATA M.2 drive for around 100 US$. However, an NVMe drive with the same storage capacity can cost you 200 US$.
Will an NVMe PCIe drive work in SATA M.2 port?
Most of the older motherboards do not support this functionality. So, a port that is made just for M.2 SATA SSD can’t accept the insertion of an NVMe SSD because of the pin placement.
i.e. The port made only for SATA M.2 will have the notch on its left side and all NVMe SSDs come with the notch at their right end. However, if a port is made for NVMe, you can easily install a SATA M.2 SSD in it and get its highest speed.
Most of the latest motherboards especially the ATX ones will come with at least two M. 2-based slots. But, it is not possible to get PCIe benefits from all of the motherboards. So, if your motherboard can’t allow the PCIe data transfer, you can’t have that speed in any way.
The main thing to note here is that if your motherboard has an M.2 NVMe, you can install either your M.2 SATA or M.2 NVMe drive, but if your motherboard works on SATA (AHCI) specifications, your NVMe drive will not work. So, before buying any NVMe SSD, consider checking whether your PCIe motherboard has support for NVMe or not.
I have published another article discussing whether an NVMe SSD can work on an M.2 port. Check that out for more.
How to check your system’s PCIe compatibility?
You can first check the official website of your computer manufacturer to see if it supports the PCIe.
The user manual of your computer/laptop/motherboard will also show you whether your motherboard supports NVMe or not.
Crucial has a great resource to help you find whether your system supports NVMe or not. You can check this page and see the results for your system as well.
For best results, consider downloading CPU-Z software and it will tell you whether your motherboard has a PCIe bus or an AHCI bus with its version.
Motherboard Compatibility for NVMe and SATA M.2
The next step is to check whether your motherboard has support for the latest NVMe. If your motherboard is working on an older M.2 version and you try to install the latest NVMe with a single notch, it will never fit there.
Also, if you try to install an M.2 SATA SSD in an NVMe support motherboard or a port, it may fit perfectly but you can never get the NVMe speed. This happens because your motherboard recognizes that drive as a simple M.2 SSD and it becomes the main bottleneck for the overall speed of your NVMe SSD.
Note: Before going for an M.2 PCIe NVMe drive, make sure to check if your BIOS supports the NVMe drive type. If it is not available there, you won’t be able to use it as your OS drive and it will remain just a storage drive for you.
Which one should you buy? M.2 SATA vs M.2 PCIe vs M.2 NVMe
As we were discussing the M.2 SATA and M.2 NVMe, I decided to add another important name which may contribute to this confusion a lot more. That name is M.2 PCIe AHCI. This is the case when your motherboard has PCIe ports but can’t work with an NVMe.
So, in my opinion, choosing the M.2 PCIe NVMe or M.2 NVMe is the best option if your motherboard supports PCIe NVMe and has an available port for the connection. It will give you more speed as compared to the M.2 SATA.
Important Note: Double-check that your laptop or PC motherboard has both PCIe and NVMe support. You will see numerous motherboards with only PCI Express support but no functionality for NVMe drives.
You will have to ignore it if you are ignoring the M.2 SATA because it is going to be bottlenecked just like the first one. The reason is that it will not increase the performance just like the NVMe drive. The price to a performance ratio will be very low.
Final Verdict
I hope you are now aware of both these types of SSD. Well, consider double-checking the type of M.2 your motherboard supports. It is a complete waste of money, time, and effort to install an NVMe SSD in a system that can only support SATA specifications.
Thanks for reading!
Frequently Asked Questions
Check the notch. M.2 NVMe SSDs have a single ‘M’ key notch, while M.2 SATA SSDs have two notches, known as the ‘B’ and ‘M’ keys.
Nope. M.2 SATA SSDs will only work in M.2 slots that support SATA. Similarly, M.2 NVMe SSDs require M.2 slots that are PCIe compatible. Always check your motherboard specifications.
Absolutely, as long as your motherboard has the appropriate M.2 slots for each type, you can use both M.2 NVMe and M.2 SATA SSDs in the same system.