Last updated: September 2, 2026

PCIe 4.0 used to be a feature you specifically shopped for.

That is no longer the case.

On current AMD AM5 and Intel desktop platforms, PCI Express 4.0 is essentially a baseline connectivity standard. Some motherboard slots run at PCIe 4.0, others at PCIe 5.0, and lower-priority expansion slots can run at still slower generations.

That last point is important: a motherboard does not have one single PCIe version.

One board can simultaneously have:

• a PCIe 5.0 x16 graphics slot,
• a PCIe 5.0 x4 M.2 socket,
• two PCIe 4.0 x4 M.2 sockets,
• a physical x16 expansion slot wired at PCIe 4.0 x4,
• and smaller chipset-connected slots using another configuration.

So if you are checking whether a motherboard supports PCIe 4.0, the next question should always be: which slot?

What is PCIe 4.0?

PCI Express is the high-speed interface used to connect devices such as:

• graphics cards,
• NVMe SSDs,
• network adapters,
• capture cards,
• storage controllers,
• and other expansion hardware.

The PCI-SIG released PCI Express 4.0 Version 1.0 in 2017 .

PCIe 4.0 doubled the signaling rate of PCIe 3.0 from 8GT/s to 16GT/s per lane.

PCIe 5.0 doubled that again to 32GT/s.

PCIe 3.0 vs 4.0 vs 5.0 bandwidth

The easiest way to understand PCI Express is to separate generation from lane count.

A faster generation increases the bandwidth of each lane. Adding lanes increases total link bandwidth.

Swipe → to see the full bandwidth table

What motherboards support PCIe 4.0 in 2026?

Practically every mainstream current desktop platform provides PCIe 4.0 connectivity.

The differences are now about where PCIe 5.0 is provided and how the remaining Gen4 lanes are divided.

Current AMD AM5 PCIe support

AMD’s own Socket AM5 chipset specifications show a clear separation between current motherboard tiers.

Current Intel motherboards and PCIe 4.0

Intel’s current LGA1851 platform also combines several PCIe generations.

Core Ultra 200S processors provide:

• up to 20 CPU-connected PCIe 5.0 lanes,
• plus four CPU-connected PCIe 4.0 lanes.

The current Z890, B860 and H810 chipsets themselves provide PCIe 4.0 expansion lanes.

Intel documents the current Z890 , B860 and H810 chipsets as PCIe 4.0-capable on their chipset expansion lanes.

What about Intel Z790, B760 and H770?

Intel’s LGA1700 700-series motherboards also support PCIe 4.0 extensively.

Intel’s specifications list:

• Z790 with up to 28 chipset PCIe 3.0/4.0 lanes,
• H770 with up to 24 chipset PCIe 3.0/4.0 lanes,
• B760 with up to 14 chipset PCIe 3.0/4.0 lanes.

The CPU can additionally supply the main graphics and NVMe connections, depending on the processor and motherboard layout.

The same broad principle applies to many Intel 600-series boards: PCIe 4.0 is not limited to one slot or one chipset block.

What about older AMD AM4 PCIe 4.0 motherboards?

On AMD’s previous AM4 platform, PCIe 4.0 became mainstream with X570 and B550.

Those boards can still be perfectly good upgrade platforms when paired with a compatible Ryzen processor.

The exact CPU matters, however.

Some AM4 processors and APUs expose different PCIe capabilities, so you should check the specific motherboard and processor rather than assuming that installing any AM4 CPU into a B550/X570 board automatically gives every slot Gen4 operation.

A motherboard does not determine PCIe speed by itself

The old version of this guide says the CPU, motherboard and PCIe device all matter, which is correct—but it needs one more layer of detail.

The active PCIe link is determined by:

1. the CPU/controller capability,
2. the motherboard trace/slot implementation,
3. the device’s maximum generation and lane width,
4. and any lane-sharing or bifurcation rules currently active.

Example: Gen5 GPU in a Gen4 x16 slot

A Radeon RX 9070 XT is specified by AMD as PCIe 5.0 x16.

Install it in a PCIe 4.0 x16 motherboard slot and the two devices negotiate a PCIe 4.0 x16 connection.

The graphics card does not become incompatible.

Example: Gen4 SSD in a Gen5 M.2 socket

A Samsung 990 PRO is a PCIe 4.0 x4 NVMe SSD.

Install it into a PCIe 5.0 x4 M.2 socket and it simply runs at its own PCIe 4.0 x4 maximum.

Example: Gen5 SSD in a Gen4 M.2 socket

A PCIe 5.0 drive such as Samsung’s 9100 PRO can also operate through a compatible Gen4 M.2 connection, but its interface bandwidth is then limited to PCIe 4.0 x4.

Is PCIe 4.0 backward compatible?

Yes.

This is not merely a practical convention. The PCI-SIG explicitly specifies backward compatibility between PCIe 4.0 and prior PCIe generations.

PCIe 5.0 continues the same model.

The PCI-SIG states that a PCIe 5.0 card can plug into a compatible PCIe 4.0 slot and operate at the highest speed supported by the link.

See: PCI-SIG PCIe 5.0 backward compatibility .

Will a PCIe 5.0 graphics card work in a PCIe 4.0 motherboard?

Yes.

Current GPUs such as:

• GeForce RTX 50-series cards,
• Radeon RX 9070,
• Radeon RX 9070 XT,
• and Radeon RX 9060 XT

support PCIe 5.0.

They remain backward compatible with PCIe 4.0 motherboards.

For normal gaming, the bigger question is whether the reduced bandwidth meaningfully changes performance.

Does PCIe 4.0 reduce GPU gaming performance?

With a full PCIe 4.0 x16 connection, normally very little or not enough to matter.

Current motherboard testing from Tom’s Hardware notes that even with today’s fastest graphics hardware, PCIe 5.0 x16/x8 versus PCIe 4.0 x16 tends to fall within margin-of-error territory for gaming.

That is important because PCIe 4.0 x16 already provides roughly 31.5GB/s of theoretical bandwidth in each direction.

Lane width can matter more than the PCIe generation printed on the box

Not every graphics card uses 16 lanes.

For example, NVIDIA’s RTX 5060 Ti uses a PCIe 5.0 x8 interface.

That means:

• PCIe 5.0 x8 provides roughly PCIe 4.0 x16-class bandwidth,
• PCIe 4.0 x8 cuts that in half,
• PCIe 3.0 x8 halves it again.

Why VRAM can make PCIe bandwidth matter more

A graphics card normally keeps frequently used textures, buffers and other assets inside its own much faster VRAM.

When the VRAM capacity is exceeded, some data can spill into system memory.

Accessing that data requires traffic across PCI Express.

That is where PCIe bandwidth can suddenly become much more important.

TechSpot demonstrated this very clearly with modern 8GB GPUs. In some VRAM-heavy games, reducing an 8GB card from PCIe 5.0 to PCIe 4.0—and especially to PCIe 3.0—could cause major performance and frame-time degradation.

By contrast, the 16GB versions often showed much smaller sensitivity because they did not need to move as much game data through system memory.

See: TechSpot’s RTX 5060 Ti PCIe scaling tests and RX 9060 XT PCIe scaling tests .

PCIe 4.0 vs PCIe 5.0 for NVMe SSDs

Storage is where the raw bandwidth difference is easiest to see.

A high-end PCIe 4.0 x4 SSD such as Samsung’s 990 PRO can reach approximately:

• 7,450MB/s sequential read,
• 6,900MB/s sequential write.

Samsung’s current PCIe 5.0 9100 PRO nearly doubles that, with up to:

• 14,800MB/s sequential read,
• 13,400MB/s sequential write on appropriate capacities.

See Samsung’s specifications for the 990 PRO and 9100 PRO .

Does a Gen5 SSD make games twice as fast as a Gen4 SSD?

No.

Sequential transfer speed is not the same as game performance.

A particularly useful 2026 Tom’s Hardware test compared gaming from SATA through multiple generations of PCIe SSD.

Across 11 games, only two showed measurable in-game performance differences between SATA and PCIe storage, and the difference between individual PCIe SSD generations was generally much smaller.

Tom’s also found that flagship PCIe drives often produce only small load-time improvements despite very large differences in headline sequential throughput.

See: Tom’s Hardware SSD gaming performance test .

When does PCIe 5.0 SSD performance actually matter?

The additional bandwidth can be useful for workloads such as:

• large sequential file transfers,
• high-resolution video scratch/cache work,
• some professional content-creation workflows,
• large datasets,
• storage benchmarks,
• and workloads specifically designed to exploit high queue depth and bandwidth.

For normal Windows use and gaming, a good PCIe 4.0 NVMe SSD remains extremely fast in 2026.

CPU-connected vs chipset-connected PCIe lanes

Not every slot takes the same path through the system.

This is why the specification “four M.2 slots” does not tell you enough.

You need to know:

• which are CPU-connected,
• which are chipset-connected,
• their PCIe generations,
• their lane widths,
• and whether any share bandwidth with another device.

Lane sharing matters more than ever

Modern CPUs provide a finite number of direct PCIe lanes.

Motherboard manufacturers have to decide how to divide those lanes between:

• the primary GPU slot,
• Gen5 M.2 sockets,
• USB4 controllers,
• additional PCIe slots,
• and other onboard hardware.

That can create configurations where installing an SSD changes another connection.

For example, some high-end AM5 boards allow a second CPU-connected M.2 socket to share the graphics lanes. Populating that socket can reduce the main graphics link from x16 to x8.

Is PCIe 4.0 x8 enough for a graphics card?

In many cases, yes.

PCIe 4.0 x8 provides roughly the same bandwidth as PCIe 3.0 x16.

Tom’s current motherboard guidance says that once you remain around PCIe 4.0 x8 or higher, gaming differences with modern GPUs are often small enough to show mainly in benchmarks.

But that should not be converted into a universal rule.

Performance sensitivity increases when:

• the graphics card has only x8 electrically,
• the PCIe generation is older,
• VRAM is insufficient,
• the workload transfers large amounts of data between GPU and system memory,
• or professional compute/render workloads use the PCIe bus more heavily than games.

Physical x16 does not mean electrical x16

A motherboard slot can be physically long enough for a full graphics card while having only four or eight electrical lanes connected.

For example, specifications may say:

• PCIe 5.0 x16 — physical x16, electrical x16,
• PCIe 4.0 x16 (x4 mode) — physical x16, electrical x4,
• PCIe 4.0 x16 (x1 mode) — physical x16, electrical x1.

Does the M.2 slot use PCIe lanes too?

Yes.

NVMe M.2 SSDs use PCI Express.

A typical high-performance M.2 connection is:

• PCIe 3.0 x4,
• PCIe 4.0 x4,
• or PCIe 5.0 x4.

That x4 lane requirement is one reason installing several high-speed M.2 SSDs can create lane-sharing decisions on consumer motherboards.

Does installing an M.2 SSD disable PCIe slots?

Sometimes.

It depends completely on the motherboard design.

Possible outcomes include:

• nothing changes,
• a lower PCIe slot becomes unavailable,
• the GPU runs at x8 instead of x16,
• a SATA port is disabled,
• USB4 bandwidth is reduced,
• or one M.2 slot is limited to a lower width.

PCIe 4.0 vs 5.0 motherboard: which should you buy in 2026?

Which AMD chipset would I choose today?

What about B840?

B840 proves that PCIe 4.0 remains completely current.

AMD specifies:

• PCIe 4.0 x16 graphics,
• PCIe 4.0 x4 NVMe,
• DDR5 memory support,
• and optional USB4 implementation.

The bigger B840 compromises are platform and expansion features, not that PCIe 4.0 has suddenly become too slow for a normal PC.

Do you need X870 just for PCIe 5.0?

Usually not.

If your gaming build uses:

• one graphics card,
• one or two SSDs,
• 2.5Gb Ethernet,
• and no USB4 devices,

a good B850 board can be the more rational purchase.

If you need USB4, richer networking or more high-speed expansion, the X870 tier becomes easier to justify.

See our Best AM5 Motherboards With USB4 if that connectivity is part of the build.

Can PCIe 4.0 affect Resizable BAR or Smart Access Memory?

No direct dependency exists requiring PCIe 5.0 for these features.

Resizable BAR allows the CPU to map a larger portion of the GPU’s frame buffer at once.

AMD brands its implementation/support ecosystem as Smart Access Memory on compatible Radeon/Ryzen configurations.

A compatible PCIe 4.0 system can use Resizable BAR normally.

What about PCIe riser cables?

If you vertically mount a graphics card, the riser becomes part of the PCIe signal path.

Use a riser designed and validated for the generation you intend to run.

A Gen3 riser between a Gen4 motherboard and Gen4 GPU can cause the link to fall back to Gen3 or create stability problems when the system tries to negotiate a faster generation.

How do I know what PCIe generation a motherboard slot supports?

Use the motherboard manufacturer’s specification page and manual.

Look for entries such as:

• PCI_E1: PCIe 5.0 x16,
• PCIEX16: PCIe 4.0 x16,
• PCIEX16_2: PCIe 4.0 x4,
• M2_1: PCIe 5.0 x4,
• M2_2: PCIe 4.0 x4.

Do not infer the electrical connection purely from slot length.

Why might a PCIe 4.0 slot run at Gen3?

Possible reasons include:

• the installed device is only PCIe 3.0,
• the CPU only supports PCIe 3.0 on that connection,
• the motherboard routes that specific slot at Gen3,
• a riser cable is limiting the connection,
• BIOS is manually configured to a lower generation,
• or signal-integrity troubleshooting has forced link retraining at a slower speed.

The negotiated speed can never exceed the slowest relevant component in that particular link.

Should you upgrade a PCIe 3.0 PC to PCIe 4.0?

Not for the PCIe label alone.

A PCIe 3.0 platform can still be useful, especially with a full x16 graphics connection and enough GPU VRAM.

But PCIe 3.0 becomes more limiting when:

• a new GPU uses only x8 lanes,
• the graphics card frequently exceeds its VRAM capacity,
• you need faster NVMe storage,
• the old CPU is already limiting performance,
• or the platform lacks other features you now need.

Should you upgrade from PCIe 4.0 to PCIe 5.0?

For a normal gaming system: usually no.

A PCIe 4.0 x16 GPU connection is still extremely capable. A high-quality PCIe 4.0 NVMe SSD is already fast enough that moving to Gen5 rarely transforms normal game performance.

Upgrade when the entire newer platform offers enough extra value, not because Gen5 doubles theoretical bandwidth.

PCIe 6.0 and PCIe 7.0 already exist—should you wait?

No.

PCI-SIG finalized PCIe 6.0 in 2022 and PCIe 7.0 in 2025.

That does not mean mainstream consumer motherboards immediately adopt those standards.

Industry specifications are intentionally completed years before some technologies become normal desktop hardware.

The consumer desktop market in 2026 is still primarily a mix of PCIe 4.0 and PCIe 5.0.

If you want the broader context of how standards reach consumer motherboards, see our History of Motherboards .

Common PCIe 4.0 motherboard mistakes

PCIe motherboard buying checklist

• Which CPU socket/platform am I buying?
• What PCIe generation does the CPU provide for graphics?
• Is the main GPU slot x16 electrically?
• Does installing an M.2 SSD reduce the main GPU slot to x8?
• Which M.2 slot is Gen5?
• Which M.2 slots are Gen4?
• Which M.2 slots connect through the chipset?
• Do any M.2 sockets share bandwidth with USB4?
• Do any M.2 sockets disable SATA ports?
• What lane width does my graphics card actually use?
• Does my workload really benefit from a Gen5 SSD?
• Would a cheaper Gen4-oriented board let me spend more on the CPU or GPU?
• Does the board have the networking, USB and expansion I actually need?

Useful Best Motherboard Zone guides

PCIe 4.0 motherboard FAQ