Answered: PCI vs. AGP vs. PCIe? Time to Upgrade! (2025)

PCI-Express is currently the dominant bus for connecting expansion cards and devices (alongside USB, which is used for externally connected devices). AGP and PCI are typically no longer relevant due to their slow throughput rates of 2133 MB/s and 533 MB/s, respectively. The modern PCI-Express bus (version 5.0), on the other hand, can reach up to 63 GB/s when 16 lanes are used.

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

PCI stands for Peripheral Component Interconnect. PCI is a computer bus used for attaching devices to a computer via expansion boards.

After PCI was introduced in 1992, computer owners could use PCI slots on a motherboard for attaching numerous types of expansion boards. PCI expansion boards include graphics cards, sound cards, modems, TV tuners, additional USB ports, and hard drive adapters.

When PCI was introduced, it replaced various other slots on a motherboard, such as ISA and VESA Local Bus (VLB).

PCI can reach a throughput of 533 MB/s.

PCI is generally no longer found on most motherboards as PCI-Express has replaced it.

AGP stands for Accelerated Graphics Port. An AGP slot on a PC's motherboard is used for connecting a graphics card to the PC. AGP was introduced in 1997 as a replacement for the slower PCI (Peripheral Component Interconnect) bus.

Rather than sharing the bandwidth of the PCI bus with other devices, AGP provides a dedicated bus for the video card. AGP had double the bandwidth compared to PCI and could read textures directly from system memory, unlike PCI, which had to copy the textures.

AGP had a throughput of up to 2133 MB/s, compared to PCI's 533 MB/s maximum.

Starting in 2004, PCI-Express began replacing AGP and PCI.

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.

PCIe 5.0 is the latest version of PCI-Express on the market.

PCIe 5.0 x16 can reach speeds of 63 GB/s.

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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.

PCI-Express Speeds (Rounded)

	PCIe 4.0	PCIe 5.0
x1 Bandwidth	2 GB/s	4 GB/s
x2 Bandwidth	4 GB/s	8 GB/s
x4 Bandwidth	8 GB/s	16 GB/s
x8 Bandwidth	16 GB/s	32 GB/s
x16 Bandwidth	32 GB/s	63 GB/s

Intel's 12th generation CPUs currently provide PCIe 5.0 support for CPU lanes (i.e., one x16 or two x8 PCIe 5.0 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.

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.

PCI-Express 3.0 Speed (Rounded)

x1 Bandwidth	1 GB/s
x2 Bandwidth	2 GB/s
x4 Bandwidth	4 GB/s
x8 Bandwidth	8 GB/s
x16 Bandwidth	16 GB/s

Intel Core Processors:
12th to 14th Gen (Alder Lake and Raptor Lake) support PCIe 5.0 on LGA 1700. These generations work with either DDR4 or DDR5 depending on the motherboard.
15th Gen Core Ultra 200 desktop (Arrow Lake) supports PCIe 5.0 on LGA 1851 and uses DDR5.

AMD Ryzen Processors:
Ryzen 7000 (Zen 4) supports PCIe 5.0 on AM5 with 28 total lanes, with 24 available to devices and 4 reserved for the chipset link.
Ryzen 9000 (Zen 5) continues full PCIe 5.0 support on AM5.
Note: Ryzen 8000G desktop APUs on AM5 are limited to PCIe 4.0.

Intel Xeon w-Series:
Xeon w-2400 and w-3400 (Sapphire Rapids) support PCIe 5.0 on LGA 4677, with up to 64 lanes on w-2400 and up to 112 lanes on w-3400.

AMD Ryzen Threadripper Series:
Threadripper 7000 (TRX50, sTR5) supports PCIe 5.0 with high lane counts for HEDT builds.
Threadripper PRO 7000 WX (WRX90, sWRX9) supports PCIe 5.0 with up to 128 lanes for workstation platforms.
Threadripper 9000 and Threadripper PRO 9000 WX continue PCIe 5.0 support with similar platform goals and very high lane counts.

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

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.

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

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!