Can I Use a PCIe 4.0 Graphics Card in a PCIe 3.0 Slot?

Can I Use a PCIe 4.0 Graphics Card in a PCIe 3.0 Motherboard Slot?

A PCIe 4.0 graphics card will work in a PCIe 3.0 motherboard slot at PCIe 3.0 speeds.

For PCIe 4.0 graphics cards, maximum graphics throughput can only barely exceed that of PCIe 3.0. For this reason, the benefits of upgrading your motherboard to PCIe 4.0 will be minor.

PCI-Express versions are backward compatible, meaning that you can use a PCIe 4.0 graphics card or storage device on a PCIe 3.0 or PCIe 2.0 system. However, PCI-Express will use speeds based on the lowest of the two versions for communication. For example, if you use a PCIe 4.0 video card with a PCIe 3.0 system, the video card would be running at PCIe 3.0 speeds.

Reducing the PCIe version would halve the max potential bandwidth. However, you may not experience a performance impact if your device is not using the available bandwidth.

You can refer to the following table to determine the bandwidth limit and decide whether that is adequate for your needs.

Recommended PCIe 4.0 Nvidia GeForce GPUs

• Nvidia GeForce RTX 3070 Ti OC
• 8 GB 256-bit GDDR6X Memory

• Nvidia GeForce RTX 3080 OC
• 12 GB 384-bit GDDR6X Memory

• Nvidia GeForce RTX 3070 Ti OC
• 8 GB 256-bit GDDR6X Memory

Can I Use an x4 or x8 Card in an x16 PCIe Slot?

You can use PCIe cards of a lower lane width (e.g., x2, x4, or x8) in a higher lane width slot (e.g., x16).

PCI-Express will negotiate how many lanes will be used, and your card will work at its full speed, assuming the PCIe slot has the same or higher PCIe version.

Is PCIe 4.0 Worth It for Gaming?

The performance improvement when upgrading graphics to PCIe 4.0 from PCIe 3.0 is currently pretty minor.

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

• Want to get every bit of extra performance out of a PCIe 4.0 graphics card
• Use the fastest NVMe storage devices for loading games, which will make use of the speed
• Want to future-proof your system
• Want to free up PCIe lanes for other devices

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

Check out the complete list of CPUs supporting PCIe 5.0 in Which Intel and AMD CPUs Support PCIe 5.0?.

Which Desktop Graphics Cards Support PCIe 4.0?

Both Nvidia and AMD graphics cards supporting PCI-Express 4.0 are available.

All graphics cards with Nvidia's GeForce RTX 30 and RTX 40 series GPUs support PCIe 4.0.

AMD's Radeon RX 5000, RX 6000, and RX 7000 series GPUs all support PCIe 4.0.

List of GPUs That Support PCIe 4.0

Find PCIe 4.0 Nvidia Graphics Cards on Amazon

Find PCIe 4.0 AMD Graphics Cards on Amazon

Are PCIe Versions Forward Compatible?

PCIe versions are forward compatible, meaning that you can use a newer PCIe device with an older system. However, PCI-Express will use speeds based on the lowest of the two versions for communication.

Check out the table above to determine what the throughput limit would be for a specific configuration.

Multiple PCIe Versions for CPU/Motherboard

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.

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!