What Is PCIe 4.0?

Intel and AMD have both released CPUs with PCIe 4.0 support. Let's dig into what PCI-Express 4.0 is and whether it's worth the upgrade.

Check out my Recommended PCIe 4.0 CPUs and Motherboards below.

Intel Core i9-11900K

What Is PCI-Express?

PCI-Express (PCIe) is an electrical bus used in nearly all modern consumer and server PCs. PCIe slots on desktop PCs allow for connecting various expansion boards, including graphics cards, sound cards, video capture cards, network/Wi-Fi cards, storage devices, and more. PCI-Express is the successor of PCI.

PCI-Express is currently the dominant bus for connecting expansion cards and devices (alongside USB, which is used for externally connected devices).

While you may recognize PCI-Express as the name used for the motherboard's expansion ports, the same bus is also used for computer storage interfaces. When PCI-Express is used for storage, the NVM Express (NVMe) storage protocol is typically used. In addition to PCIe slots, motherboards provide a high-speed PCIe connection to devices via connectors such as M.2 and U.2.

Learn more about storage types in Storage Type Comparison: M.2, U.2, NVMe, SATA, SSDs, HDDs

PCIe Slots on a Motherboard Eric Kilby

What Are PCI-Express Lanes?

PCIe lanes are connections between a PCI-Express expansion card or device and the CPU. PCIe lanes often communicate with the CPU via chipsets on the motherboard. Each PCIe lane is composed of 4 wires (two differential pairs).

With naming similar to a road, the number of lanes is referred to as the lane size, or how many lanes wide a link or port uses. A single lane is referred to as x1 or "one lane wide."

The maximum throughput (speed) is multiplied by the number of lanes. An x8 PCIe port has twice the throughput of an x4 port.

Some CPUs and motherboards provide PCI-Express lanes at multiple PCIe versions. In these cases, you can choose which devices need the most bandwidth to decide which should be connected to the highest version PCIe lanes. While laying out your system, keep in mind that PCIe speeds will be based on the lowest PCIe version between the slot/port and the device.

You can insert a PCIe add-in card (AIC) into a slot that supports a higher number of lanes. In this case, it would use up to the number of PCIe lanes that the card has. For example, you could insert an x4 PCIe network card into an x16 PCIe AIC slot, and it would run at full x4 speed.

In various scenarios, a PCIe device may not use the maximum number of lanes for which the device was designed. For example, some motherboards have x8 PCIe ports that are only electrically wired for x4 lanes. In another case, a system may have limited lanes provided by the CPU, distributed based on availability or configuration.

Devices will negotiate the number of lanes to use, based on system availability, and should still perform fine at a reduced overall bandwidth in most cases. Refer to your motherboard's documentation and CPU specifications to determine PCIe lane quantities and allocations.

PCIe 4.0 Benefits

The key benefit of upgrading to PCI-Express 4.0 is the increased bandwidth. Each version of PCIe roughly doubles the bandwidth available per lane.

Any devices which were designed for PCIe 4.0 can benefit from the increase in available bandwidth.

Devices designed for PCIe 4.0 could mean faster storage speeds (video and game loading) and faster graphics (video games and rendering).

However, some devices may not even be reaching the limits of PCIe 3.0 yet. The low bandwidth usage by some devices means that it's only necessary to upgrade if:

• You are using the latest and fastest storage devices and video cards, which make use of the PCIe 4.0 lanes.
• You want to free up PCIe lanes by using PCIe 4.0 devices, which won't need as many lanes for the same bandwidth.
• You want to future-proof your system.

The component which can benefit the most from PCIe 4.0 is NVMe storage. The latest top-performing NVMe SDD and add-in card (AIC) storage devices can benefit from both the higher throughput and the throughput available per lane.

With each PCIe version doubling the bandwidth per lane, newer devices can reduce the number of needed lanes. For example, if even the top tier of graphics cards no longer need the full 16 lanes to meet their needs, they can use 8 or fewer lanes. By using fewer lanes, it frees up more lanes for other devices. Using fewer lanes is important because CPUs provide a limited number of lanes, which need to be distributed among the devices.

The same is valid for storage. If your storage devices no longer need as many lanes, PCIe add-in card (AIC) adapters can connect more NVMe M.2 SSDs.

For networking, a single lane could now provide enough bandwidth for 10 Gbps Ethernet.

If you are building a new system, it may make sense to do the upgrade to 4.0. In particular, future graphics cards and storage devices may further take advantage of this available bandwidth. In this case, you might consider how long you plan to use this computer. For example, will you upgrade your storage and graphics card over the next few years or wait to replace the entire system?

Is PCIe 4.0 Worth It for Gaming?

It is worth the upgrade to PCIe 4.0 for gaming if you:

• Use the fastest NVMe storage devices for loading games, which will make use of the speed
• Have a PCIe 4.0 graphics card, which may see a slight performance improvement
• Want to future-proof your system
• Want to free up PCIe lanes for other devices

Check out my Recommended PCIe 4.0 CPUs and Motherboards below.

Check out the complete list of CPUs supporting PCIe 4.0 in Which Intel and AMD CPUs Support PCIe 4.0?

Which Desktop and Workstation PCIe 4.0 CPUs Are Available?

Most of AMD's Ryzen 3000 and 5000 series, Ryzen Threadripper 3000 series, and Ryzen Threadripper Pro 3000 series processors support PCIe 4.0. Intel's 11th generation processors, code-named "Rocket Lake," support PCIe 4.0.

AMD Ryzen 9 5900X

Check out my Recommended PCIe 4.0 CPUs and Motherboards below.

Check out the complete list of CPUs supporting PCIe 4.0 in Which Intel and AMD CPUs Support PCIe 4.0?

Which Motherboards Support PCIe 4.0?

To get full PCIe 4.0 support, you'll need to use a motherboard with the chipsets listed below.

• For Intel's 11th generation processors, you'll need a motherboard with the Z590 or B560 chipset for full PCIe 4.0 support.

  • Find Z590 Chipset 11th Gen Motherboards on Amazon (affiliate link).
  • Find B560 Chipset 11th Gen Motherboards on Amazon (affiliate link).
  ASUS ROG Maximus XIII Hero Z590 Check Price on Amazon Amazon Affiliate Link

• For AMD's Ryzen processors, you'll need a motherboard with the X570 chipset for full PCIe 4.0 support.

  Often, a different BIOS is required for Ryzen 3000 and Ryzen 5000 processors. To avoid updating the BIOS, you can purchase a motherboard marked as "ready" for the processor series. If you plan to update the BIOS, motherboards with the USB BIOS Flashback feature simplify this process; they do not require an installed compatible processor.

  • Find X570 Chipset Ryzen 3000 Motherboards on Amazon (affiliate link).
  • Find X570 Chipset Ryzen 5000 Motherboards on Amazon (affiliate link).
  MSI MAG X570 TOMAHAWK WIFI Check Price on Amazon Amazon Affiliate Link

Our Recommended PCIe 4.0 CPUs and Motherboards

• Up to 4.8 GHz: perfect for games, video editing, and high-intensity tasks.
• 12 cores / 24 threads: High core count for the frequency! This combination makes it a great all-around system that can handle almost any job.
• Check the latest price of the AMD Ryzen 9 5900X on Amazon (affiliate link). AMD Ryzen 9 5900X Check Price on Amazon Amazon Affiliate Link
• For the AMD Ryzen 9 5900X CPU, you'll need a 5000 series motherboard with the X570 chipset to support PCIe 4.0.
• Our recommended motherboard to pair with the Ryzen 9 5900X is MSI's MAG X570 TOMAHAWK WIFI Motherboard: MSI MAG X570 TOMAHAWK WIFI Check Price on Amazon Amazon Affiliate Link
  • PCIe 4.0 support
  • One 2.5 Gb Ethernet port is faster than most Internet speeds, with room to spare for file transfers.
  • Two NVMe M.2 slots both run at PCIe 4.0 speeds.
  • Wi-Fi 6 provides great Wi-Fi speeds (not Wi-Fi 6E, but still really good).
  • USB 3.2 Gen 2 offers 10 Gbps USB speeds.
  • Check the latest price of the MSI MAG X570 TOMAHAWK WIFI Motherboard on Amazon (affiliate link).

• Up to 5.3 GHz: perfect for games, video editing, and high-intensity tasks.
• 8 cores / 16 threads: Quite a few cores considering the frequency! This combination makes it a great all-around system that can handle almost any task.
• You'll want to use a good cooler, as the "Thermal Velocity Boost Frequency" feature will improve your clock speed based on how cool you can keep it.
• Virtualization features make it great for running virtual machines.
• Check the latest price of the Intel Core i9-11900K on Amazon (affiliate link). Intel Core i9-11900K Check Price on Amazon Amazon Affiliate Link
• For the Intel Core i9-11900K CPU, you'll need a motherboard with the Z590 or B560 chipset to support PCIe 4.0.
• Our recommended motherboard to pair with the i9-11900K is ASUS's ROG Maximus XIII Hero: ASUS ROG Maximus XIII Hero Z590 Check Price on Amazon Amazon Affiliate Link
  • Four NVMe M.2 slots, which is great! (two @ PCIe 4.0 speeds, two @ PCIe 3.0 speeds).
  • This board includes various headers for accessories, including 3 ARGB headers for lighting control and separate AIO and water pump headers.
  • Audio noise canceling and an optical audio output port
  • Z590 chipset supports overclocking for K-prefixed CPUs.
  • PCIe 4.0 support
  • Wi-Fi 6E makes it easy to reach the fastest speeds and future-proof your Wi-Fi system.
  • Bluetooth 5.2 is great for streaming music to Bluetooth headphones.
  • Two 2.5 Gb Ethernet ports are faster than most Internet speeds with room to spare for file transfers.
  • USB 3.2 Gen 2x2 offers 20 Gbps USB speeds!
  • Check the latest price of the ASUS ROG Maximus XIII Hero on Amazon (affiliate link).

• Half the price of the i9-11900K, but still excellent performance at up to 4.9 GHz.
• 6 cores / 12 threads: There are a decent number of threads to make it good at everyday multi-threading tasks, such as having tons of browser windows open.
• Check the latest price of the Intel Core i5-11600K on Amazon (affiliate link).
• Intel Core i5-11600KF (affiliate link) is a backup option if this one isn't in stock. It is the same other than the lack of integrated graphics support. Intel Core i5-11600K Check Price on Amazon Amazon Affiliate Link
• For the Intel Core i5-11600K CPU, you'll need a motherboard with the Z590 or B560 chipset to support PCIe 4.0.
• Our recommended motherboard to pair with the i5-11600K is the ASUS TUF Gaming Z590-Plus WiFi motherboard: ASUS TUF Gaming Z590-Plus WiFi Check Price on Amazon Amazon Affiliate Link
  • Three NVMe M.2 slots, which is excellent (one @ PCIe 4.0 speeds, two @ PCIe 3.0 speeds).
  • PCIe 4.0 support
  • Wi-Fi 6 makes it easy to reach the fastest speeds and future-proof your Wi-Fi system.
  • One 2.5 Gb Ethernet port, which is faster than most Internet speeds with room to spare for file transfers.
  • USB 3.2 Gen 2x2 offers 20 Gbps USB speeds!
  • Check the latest price of the ASUS TUF Gaming Z590-Plus WiFi on Amazon (affiliate link).

What Is the Latest Version of PCI-Express?

The latest available version of PCI-Express is PCIe 5.0. PCIe 5.0 CPUs are available from Intel and AMD.

Intel's 12th and 13th generation Core CPUs currently provide PCIe 5.0 support for CPU lanes (i.e., one x16 or two x8 PCIe slots) and PCIe 4.0/3.0 speeds for the remaining lanes.

AMD's Zen 4-based Ryzen 7000 desktop CPUs are their first to support PCIe 5.0.

PCIe versions such as 3.0, 4.0, and 5.0 are sometimes informally referred to as PCIe Gen 3, PCIe Gen 4, and PCIe Gen 5. This naming is based on them being the third, fourth, and fifth generations of PCI-Express.

PCIe 5.0 graphics cards and storage devices are not currently on the market.

How Fast Is PCIe?

PCI-Express speeds are based on the PCI-Express version and the number of lanes used. One lane is referred to as x1, two lanes as x2, etc. PCI-Express technically supports up to a width of x32. However, most consumer motherboards have some set of these PCIe widths: x1, x2, x4, x8, x16.

Intel's 12th generation CPUs currently provide PCIe 5.0 support for CPU lanes (i.e., one x16 or two x8 PCIe slots) and PCIe 4.0/3.0 speeds for the remaining lanes.

The bandwidth for each PCIe 5.0 lane is 4 GB/s. 4 GB/s per lane means that if you use a PCI-Express 5.0 x16 device, it would have up to 64 GB/s of bandwidth available to it.

NVMe M.2 SSD cards use 2 or 4 lanes, which means they have 4–8 GB/s available to them with PCIe 4.0.

Samsung 980 1 TB M.2 SSD

NVMe PCIe add-in cards can use up to 16 lanes in an x16 slot, thus having up to 32 GB/s of bandwidth available to them with PCIe 4.0.

In comparison, PCIe 3.0 has half of the bandwidth of PCIe 4.0.

Other Considerations When Building a PC

Want to brush up on other new technologies to consider when building a computer? Check out these articles:

• Cases:
  • How to Choose the Best PC Case
• CPUs:
  • The Best CPUs for Gaming
  • Which Intel and AMD CPUs Support PCIe 5.0?
  • Which Intel and AMD CPUs Support PCIe 4.0?
  • LGA 1700 CPU List
  • LGA 1200 CPU List
  • Look up an Intel or AMD CPU on TechReviewer for related recommendations:
• CPU Coolers:
  • What is the Best Type of CPU cooler for a Gaming PC?
  • How to Choose a CPU Cooler for Your PC
  • Best LGA 1700 CPU Cooler for Intel's 12th Gen Core Processors
  • Best AM4 CPU Cooler for AMD Processors
• Storage:
  • Can an SSD Improve PC Gaming Performance? and Does an SSD Increase FPS for PC Gaming?
  • Storage Type Comparison: M.2, U.2, NVMe, SATA, SSDs, HDDs
• Memory:
  • How to Choose the Best RAM for Your PC
  • How Much RAM Do You Need for Gaming? and Is 32 GB of RAM Worth It for Gaming?
  • DDR4 vs. DDR5? Which You Should Buy
  • Is DDR5 Worth It? The Benefits of DDR5 and What Is DDR5?
  • Which Intel and AMD CPUs Support DDR5?
• PCI-Express:
  • Is PCIe 5.0 Worth It?
• Motherboards:
  • Which Motherboards Support PCIe 5.0?
  • Which Motherboards Support PCIe 4.0?
  • Which Motherboard Should You Buy for Intel's 13th Gen CPUs?
  • Which Motherboard Should You Buy for Intel's 12th Gen CPUs?
• Graphics Cards:
  • Which Graphics Cards Support PCIe 4.0?
• Power Supplies:
  • How to Choose the Best Power Supply for a Gaming PC
  • How to Choose a PC Power Supply
• Keyboards:
  • Best Mechanical Keyboard for Gaming
• Monitors:
  • How to Choose a Gaming Monitor

Learn More About PCI-Express

Want to brush up on the latest PCIe products, versions, and features? Check out the articles in this PCI-Express series:

• What is PCIe?, What is PCIe 5.0?, and What is PCIe 4.0?
• Is PCIe 5.0 Worth It? and Is PCIe 4.0 Worth It?
• Which Intel and AMD CPUs Support PCIe 5.0?
• Which Intel and AMD CPUs Support PCIe 4.0?
• Which Motherboards Support PCIe 5.0?
• Which Graphics Cards Support PCIe 4.0?
• How Fast is PCIe 5.0? and How Fast is PCIe 4.0?
• Is PCIe Backward Compatible?
• Can I Put a PCIe x4 or x8 Card in an x16 Slot?
• Can I Use a PCIe 4.0 NVMe SSD in a PCIe 3.0 Motherboard Slot?
• Can I Use a PCIe 3.0 NVMe SSD in a PCIe 4.0 Motherboard Slot?
• Can I Use a PCIe 4.0 Graphics Card in a PCIe 3.0 Slot?
• Can I Use a PCIe 3.0 Graphics Card in a PCIe 4.0 Slot?
• What is the Latest Version of PCIe?
• PCI vs. AGP vs. PCIe? Time to Upgrade!