PCI 4.0 vs. 3.0: is it time to update your main card?

PCI 4.0 vs. 3.0: is it time to update your main card?

PCIexpress (PCIe) is one of the most important technologies in modern main cards, which helps you make the most of the fastest SSDs with the most powerful graphics cards. PCIe 4.0 still doesn't have much use, but it has great potential. PCIe 3.0 has the largest installed base until even 2020. Do you feel lost among so many technological terminology? You don't know if you should update your computers? It is normal, do not worry: here we will explain the advantages and disadvantages of PCI 4.0 vs. 3.0.


PCIe 3.0 has been available on a large number of main cards since 2010, and remains the PCIe port with the largest installed base even in 2020. It is located on the main cards of the 300 and 400 series for the first and first Ryzen processors AMD second generation, as well as Intel 300 series cards used for its eighth and ninth generation processors. It is also found in most of the main cards released during some years before these generations of processors.

PCIe 4 made its debut with AMD Ryzen third-generation processors on its 500-series main cards, specifically with the x570 chipset. In early 2020, the only main cards that support PCIe 4 are based on the AMD x570 chipset.

Intel has not made any official commitment to support PCIe 4 on compatible main cards, although it has launched its own PCIe 4 SSDs. Some rumors suggested that Intel debuted PCIe 4 with its tenth generation Comet Lake processors, but that due to problems to implement it, Intel had to reject the function, according to Toms Hardware. Meanwhile, our own reports have revealed internal documents confirming that Intel's new Xe main graphics cards will use PCIe 4.

However, the main cards can still be technically compatible, so it may be that when next-generation Rocket Lake processors debut in 2021, existing Comet Lake boards can get the feature with an update.

Another speculation says that Intel can skip PCIe 4 altogether and instead drive the recently standardized PCIe 5 with future generations of processors.


PCI 4.0 vs 3.0

The biggest advantage of PCIe 4 over PCIe 3 is its speed or overall bandwidth. Like previous generations of PCIe, PCIe 4 doubles its bandwidth with respect to the last generation, increasing bandwidth per lane to 2 gigabytes per second (2GBps). With options for 1x, 2x, 4x, 8x and 16x slots, that increases the maximum potential bandwidth for a PCIe 4 slot to 64GBps.

This gives everything that connects to a PCIe slot more free space, but for more powerful graphics cards, that really isn't necessary yet. The 2080 Ti, the most powerful conventional graphics card ever created, does not come close to saturating a PCIe 3 x16 slot, it only sees a bottleneck in the PCIe 3 x8 slots, as TechPowerUp demonstrated in its 2018 tests.

Where you can take full advantage of this additional bandwidth is with other types of additional cards. More specifically, storage, multiple PCIe 4 NVMe SSDs can operate in configuration with a RAID 0 to offer sequential read / write speeds of up to 15 GBps.

Additional lanes and compatibility

With small real-world tasks that can take advantage of the full bandwidth of the PCIe 4 x16 slots, the main advantage of this, at least in the near future, is the reduction of lane requirements for additional main card and devices. Instead of a 10 Gigabit network card that requires multiple PCIe 3 lanes, it can be output with only a 1x slot. The main graphics cards can operate at 4×8 PCIe speeds, enjoying the same bandwidth as the 3×16 PCIe slots, but with half the lanes used.

Those additional lanes can be released for additional devices in larger constructions, or allow faster devices to operate in smaller PCIe slots for more compact systems.

The support boards are also not limited to PCIe 4 devices since these are fully compatible with previous versions, which means that any previous generation PCIe device, whether first, second or third generation, works well with PCIe 4.

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