How Many M.2 Slots Do Motherboards Have?

SSDs are the new norm for storage these days. Whether you want a faster PC or plan on building a new one from scratch, SSDs are the perfect ingredient for better performance.

Generally, a typical SSD requires an M.2 slot to plug into your PC. Compared to a SATA slot – the traditional slots used for hard drives – M.2 slots are rarer, which begs the question, how many M.2 slots do motherboards have?

The answer to that question highly depends upon what motherboard you have. You can have 1 – 6 M.2 slots on a modern motherboard.

In the following text, I will talk about how many M.2 slots a motherboard typically has and some basics on how to check how many M.2 slots you have on your motherboard.

A Little Primer: SATA vs. PCIe SSDs

For starters, know that there are two interfaces that SSDs may use, SATA and PCIe.

SATA SSDs

SATA SSDs use the slower SATA interface. This is the same interface that typical hard disk drives use. As such, the maximum transfer speed of a SATA SSD is 550 MB/s.

There are two types of SSDs: 2.5″ SATA SSDs and M.2 SATA SSDs.

SATA SSD Connectors power data
2.5″ SATA SSDsĀ 

2.5″ SATA SSDs DO NOT require an M.2 slot. They use the typical SATA data and power ports on a hard disk drive.

M.2 SATA SSDs, on the other hand, require an M.2 slot with SATA support. These look like your typical M.2 sticks:

What are SATA Ports Used For
Samsung Evo 860 SATA SSD with M.2 form factor with B+M Key.

M.2 PCIe/NVMe SSD

These are the wonder SSDs that you should aim for. Most modern systems feature these SSDs, and if you plan on upgrading, M.2 PCIe SSDs, aka NVMe SSDs, are what you should aim for.

samsung 980 pro
Samsung 980 Pro. PCIe 4.0 NVMe SSD with M Key.

Depending on what version they conform to, you can have speeds of 3500 MB/s on Gen 3 NVMe SSDs and 5500 MB/s on Gen 4 NVMe SSDs.

Also Read: How to Use Two M.2 SSD?

So How Many M.2 Slots Do Motherboards Have?

Well, the answer to that question depends upon what type of motherboard you have.

The amount of M.2 slots in a motherboard largely depends upon its chipset and the CPU installed. Specifically, it relies on the amount of PCIe lanes the motherboard chipset and the CPU attached to it offers.

For installing an NVMe SSD on an M.2 slot, the slot must have 4 x PCIe lanes.

As such, the more PCIe lanes a system has, the more M.2 slots it can offer!

The following table explains how many PCIe lanes different motherboard chipsets have:

ManufacturerChipsetPCIe LanesCategory
IntelZ69028
- 12 x v4.0
- 16 x v3.0
High Performance
H67024
- 12 x v4.0
- 12 x v3.0
High Performance
(Minus overclocking Support)
B66014
- 6 x v4.0
- 8 x v3.0
Mid Range
H61012
- 12 x v3.0
Budget
Z59024High Performance
Z49024High Performance
B46016Mid Range /
Mainstream
B56012Mid Range /
Mainstream
X29924Workstation
H5104Budget
AMDX57016High Performance
B55010Mid Range
A5206Budget
TRX4016Workstation
  • For Intel chipsets, not all PCIe lanes mentioned above are user accessible. Some are reserved for built-in systems.

Again, the lanes shown above are just the chipset lanes. You must add the CPU lanes to tally the system’s total number of PCIe lanes.

Newer Gen Intel and AMD CPUs have 20 PCIe lanes. Older CPUs may offer 16 PCIe lanes.

As such, if you have an older motherboard, you may notice caveats stating that a specific M.2 slot will NOT work unless you have newer-gen CPUs.

For instance, the following is an excerpt from the technical specs for the ASUS Z590A Prime motherboard.

ASUS Primze Z590 SSD NVMe PCIe 11th gen
One of the M.2 slots requires an 11th Gen CPU. Source: ASUS

This motherboard has 3 x M.2 slots. However, one will ONLY work if you have an 11th Gen Intel CPU. Why? Because 10th and older gen Intel CPUs have 16 PCIe lanes. 11th Gen and newer have 20 PCIe lanes.

The first M.2 slot is connected to the 4 PCIe lanes of the CPU, which only the 11th or the newer Gen GPUs have.

Form Factor also Matters for M.2 Slot Count.

motherboard form factor comparison
Comparing different motherboard form factors. Source: Wikimedia.

The smaller the motherboard, the fewer the M.2 slots it would typically have.

Form Factor No. of M.2 Slots (Range) Typical Number of M.2 Slots
EATX 5-6 5
ATX 2-5 3
Micro ATX 1-3 2
Mini ITX 1-2 2

EATX motherboards, of course, the workstation motherboards, have the highest amount of M.2 slots.

ATX, Micro ATX, and Mini ITX TYPICALLY have 2, 2, and 3 slots, respectively.

I have only considered the newer chipsets from the AMD 500 and the Intel 400, 500, and 600 series.

Also Read: Are All Motherboards the Same Size?

Typical Number of M.2 Slots Found on Different Motherboard Chipsets

The table below shows all the newer motherboard chipsets and the amount of M.2 slots you can find on motherboards featuring the respective chipset.

A bit of a primer on the motherboard chipset, though. Both AMD and Intel have different chipsets for commercial motherboards.

AMD has the A, B, and X series:

  • A series, such as the A520, is found on budget motherboards
  • B series, such as the B550, is located on mid-range motherboards
  • X series, such as X570, is found on the high-end motherboards

Intel has the H, B, and Z series; H is further divided into two chipset series such that:

  • H*10, such as the H610, is for budget builds
  • B*60, such as the B660, is for mid-range builds
  • H*70, like the H670, is for high-end builds without overclocking support.
  • Z*90, such as the Z690, is for premium builds with overclocking support.

Note “*” asterisk sign marks the generation.

As such, the more premium a chipset your motherboard has, the higher the chances of featuring a higher number of M.2 slots.

This table explains it further and should give you an idea about how many M.2 slots to expect for a given chipset.

MakeChipsetNo. of M.2 Slots (Range)Typical Number of M.2 Slots
IntelZ6902-54
H6702-43
B6601-32
H6101-21
AMDX5701-62 -3
B5501-42
A5201-21
  • Note the samples were taken from the newer Intel 600 and AMD 500 series chipsets.

Intel Z and AMD X series naturally have the highest number of M.2 slots, typically concerning the maximum number. They usually can have 3 x M.2 slots on an ATX form factor, and for the high-end models, they can offer 5-6 M.2 slots as well.

Besides the chipset and the motherboard size, many other factors can contribute to how many m.2 slots the motherboard has.

For instance, if a motherboard features more PCIe expansion slots, that can reduce the number of M.2 slots since the system has limited PCIe lanes.

Besides knowing how many M.2 slots you have, you must also consider whether a particular SSD will be compatible with your motherboard.

I recommend reading this article: How to Check SSD Compatibility?

FAQ

How Many M.2 Slots Do I Have?

To check how many M.2 slots my motherboard has, you can:

  1. Check physically on the motherboard
  2. Read the specifications

A typical M.2 slot looks like this:

M.2 Slot Length
A usual M.2 slot with the different lengths marked. The holes at different length intervals are where you would screw in your SSD. Source: rog.asus.com

Reading the specification of your motherboard is the best and the most definitive way to figure out how many M.2 slots it has, including its type and the SSD type and generation they support, i.e., SATA SSD, Gen 3 NVMe, Gen 4 NVMe, etc.

how many M.2 slots do motherboards have
M.2 slots on MSI MEG B550 Unify. This motherboard has 4 x M.2 slots. Source: MSI

Also Read: How to Tell if My M.2 Slot is NVMe or SATA?

How Many M.2 Slots Can I Use?

You can use as many M.2 slots as your motherboard has available.

However, again, you must refer to the specifications to check for caveats with specific M.2 slots.

For instance, here:

ASUS Primze Z590 SSD NVMe PCIe 11th gen

One of the M.2 slots can ONLY be worked if you have an Intel 11th Gen CPU installed.

Do Motherboards Have Multiple M.2 Slots?

The majority of the newer motherboards have multiple M.2 slots.

Older and budget-friendly motherboards may have one M.2 slot only.

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Author:

Ojash
Ojash Yadav is the lead technical writer and resident tech guru at PCGuide101. He is a computer science graduate with over 8 years of experience in the IT field and a wealth of knowledge about computer peripherals. He has a passion for breaking down complex technical concepts and his goal is to make sure that our readers understand the technical details of the products they're interested in without getting lost in jargon. Ojash has over a decade of experience writing about the latest and greatest in the tech world, his articles have been featured in many popular tech publications and he's known for his thorough and unbiased reviews. He conducts extensive research and testing on the latest products to ensure our readers always get the most reliable information possible.

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