Why M.2 NVMe Drives Might DISABLE Your SATA Ports

There’s nothing more frustrating than installing your new M.2 NVMe drive only to find out that it disabled your old SATA SSD. This can be tiring, but the fix for this issue is actually pretty easy.

M.2 NVMe drives use two physical PCIe lanes, while M.2 SATA drives and SATA SSDs use one PCIe lane. Your motherboard only has so much physical bandwidth and this means it is going to disable the physical SATA ports that overlap with some of its M.2 slots. Your motherboard’s manual will list exactly which M.2 slots block out which SATA ports.

Let’s get granular with how motherboards work and why your new M.2 NVMe drive has disabled some of your SATA ports.

A Little Background for M.2 NVMe Drives

Two M.2 SSD drives and various heat sink components
Two M.2 SSD drives and various heat sink components

M.2 NVMe drives are the latest tech craze when it comes to storage. They are faster, smaller, and, in general, better than SATA SSDs. However, there’s a lot of confusion about what M.2 NVMe drives are and how they work.

Let’s take a close look at the three big factors of these new drives: M.2, NVMe, and PCIe slots.

What is a PCIe Lane, Anyway?

It’s worth it to take a little stroll down the PCIe lane. Here’s what we mean (and why so many people get this confused.)

PCIe stands for peripheral component interconnect express. It’s a type of physical connection that lets you add peripheral devices to your motherboard. This can be used to add storage, graphics cards, and other devices. PCIe comes in a few sizes.

PCIe usually comes in a few sizes ranging from: x1, x4, x8, x16, and x32. However, you’re most likely to see x4 through x16 on consumer devices. The ultra-powerful x32 does exist, but that’s reserved for industrial applications; consumer tech, like games, couldn’t even make use of x32 yet anyway, so there’s no loss there.

These PCIe lanes can be single or double-sided. This describes a physical copper wire that runs down the length of the lane.

Here’s a trick with PCIe lanes. They can be labeled x16, but only have x8 capability. Your PCIe lane might be sized for bigger devices, but only have the power to support smaller tech. You can still plug in an x16 device, but you’ll get x8 power.

Is M.2 the Same as NVMe?

CrystalDiskInfo showing an NVMe SSD installed in the PCIe 4 slot
CrystalDiskInfo showing an NVMe SSD installed in the PCIe 4 slot

Well, this is actually the heart of a lot of confusion on this issue. M.2 NVMe drives are a common combination when it comes to adding storage, but they aren’t the whole story.

M.2 and NVMe are actually two separate things. You could have an M.2 device that isn’t NVMe, for example.

M.2 describes a physical size. It’s a designation for the form factor that many cutting-edge storage options are taking due to their compact size.

NVMe stands for nonvolatile memory express. This doesn’t describe the physical size of your device, but rather how it transmits data. NVMe is the latest, and fastest, standard for flash memory data transfer.

Do M.2 NVMe Drives Disable SATA Ports?

A SATA cable and power cable
A SATA cable and power cable

The answer to this question is a little complicated.

It’s true that M.2 NVMe drives disable SATA ports, but how they disable these ports is pretty interesting. Some M.2 ports use the same physical pathways as SATA ports on your motherboard. This causes the motherboard to disable certain SATA ports if it detects a device in the corresponding M.2 slot.

Each motherboard takes a different approach to disabling SATA ports. Some motherboards disable SATA port 2, while others cut off 5 and 6 when they detect an M.2 NVMe or an M.2 SATA drive. Your motherboard’s manual will tell you which ports it disables, and under which conditions it makes those decisions.

So, why do motherboards cut off SATA ports when they detect M.2 devices? The answer has to do with bandwidth and the PCIe lanes we talked about earlier.

SATA and NVMe are, essentially, two ways of doing the same job. SATA is a slower, older protocol while NVMe is the newer, faster one. NVMe gets its speed boost, in part, by using multiple PCIe lanes.

When your motherboard detects an M.2 device, it needs to give it bandwidth in order for it to work. This means it takes bandwidth away from the slower SATA ports to support M.2 drives.

If your M.2 drive uses the SATA protocol, your motherboard typically blocks out one physical SATA port. When your M.2 drive uses NVMe, which needs an additional PCIe lane, it blocks out two physical SATA ports.

Here’s the big takeaway. Your M.2 drives use either the same, or more, physical bandwidth as your SATA SSDs. Your motherboard balances its bandwidth by shutting down SATA ports to accommodate M.2 drives. Otherwise, you’d have two drives one the same lanes which would only cause problems.

How to Fix, Troubleshoot, and Workaround M.2 NVMe Drives Disabling SATA Ports

Fixing this issue comes down to understanding your motherboard, how your drives are physically installed, and understanding your PC needs. Let’s dive into three quick fixes for these issues.

Read Your Motherboard’s Manual

An ASUS TUF Gaming B550M Plus motherboard for AMD Ryzen
An ASUS TUF Gaming B550M Plus motherboard for AMD Ryzen

It all starts here. Your motherboard’s manual is the most underutilized piece of kit in your entire PC build. You can think of your motherboard’s manual as the secret tome containing all of the lore you need to master your PC build.

Everything you connect to your PC goes back to your motherboard. It’s the core of your build. Your motherboard’s manual will tell you exactly which SATA ports get disabled and under which conditions.

This information will be vital for your overall build and how we handle the next two fixes.

Move Your Drives Around

An older SATA6 SSD with SATA cable attached
An older SATA6 SSD with SATA cable attached

There’s a limit to the amount of drives you can get connected to your motherboard. Even though you might have more ports and slots than you’re using, your motherboard is only designed to operate with so many different devices connected to it at a single time. This comes down to computational limits as well as the limits it has physically.

You can make the most of how you allocate your drives by using your motherboards manual and moving your drives around. Certain M.2 slots on your motherboard will block out certain SATA ports. You can use this information to change where your drives are physically plugged in order to get the optimum layout.

The best time to make these decisions is when you buy your PC build. It can be a lot harder to move things around later on especially when you have a large graphics card that could be physically limiting how you arrange your other drives.

Also keep in mind that not all M.2 drives are the same. As we mentioned earlier, M.2 is just a form factor and that means that it can come in both SATA and a NVMe. The drives that come in NVMe are going to block out more SATA ports, but they’re also going to give you improved speed.

Get Drives With More Storage

One of the biggest issues this causes is that it’s harder to expand the storage of your PC build when your M.2 devices start blocking out your SATA ports. You might be wanting to plug in some extra storage capacity through a SATA port, but when you finally go to install a new drive, you find out if the port has been disabled by the layout of your other drives.

The problem here is that you simply can’t plug in too many devices to your motherboard. If you’re looking to expand your storage options, you might be better served by getting drives with larger storage capacities rather than adding more drives with smaller storage limits to your PC.

This solves the problem having SATA ports that are disabled while still giving you the storage options that you’re looking for.

cropped A picture of me Tristan
About Tristan Perry

Tristan has been interested in computer hardware and software since he was 10 years old. He has built loads of computers over the years, along with installing, modifying and writing software (he's a backend software developer 'by trade').

Tristan also has an academic background in technology (in Math and Computer Science), so he enjoys drilling into the deeper aspects of technology.

Tristan is also an avid PC gamer, with FFX and Rocket League being his favorite games.

If you have any questions, feedback or suggestions about this article, please leave a comment below. Please note that all comments go into a moderation queue (to prevent blog spam). Your comment will be manually reviewed and approved by Tristan in less than a week. Thanks!

2 thoughts on “Why M.2 NVMe Drives Might DISABLE Your SATA Ports”

  1. Hello, and thank you very much for this very interesting and informative article.

    I would like to build a DIY NAS under the Unraid OS.
    The advantage here is that there is no need for a system disk (just use a USB key to boot). On the other hand, in addition to using the different SATA ports to build my Unraid array, I would like to install two NVMe SSDs to build a cache area in raid1…

    Do you know where I’m coming from? In the conclusion with your article, you indicate that it is preferable to turn to discs of greater capacity. I understand that, but what if you want to add new disks to a NAS-type solution?

    My main question is as follows: When the use of two NVMe SSDs disables certain SATA ports, can an additional PCI-E card be used to obtain functional SATA ports?

    Thanks in advance for your feedback,


    • Hello bastien,

      Thanks for the comment, that sounds an interesting project for sure.

      That all sounds a good plan – and it’s an interesting idea to use the USB drive for boot, then the NVMe drives for your main storage.

      Regarding your question – I haven’t tried it myself, but I’m 99% sure that you can use a PCI-E card to obtain new SATA ports. In this case, the motherboard isn’t provided the SATA ports – it’s the actual card that is doing that, then ‘converting’ the SATA into PCI-E. I haven’t heard anything to suggest that this wouldn’t work.



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