Skip to main content

PCIe 4 vs. PCIe 3: Is it time to upgrade your motherboard?

PCIexpress 4 doesn't have much use yet, but it has heaps of potential

PCIexpress (PCIe) is one of the most important technologies on modern motherboards, helping to get the most from the fastest SSDs to the most powerful graphics cards.

But depending on which board you buy, you may have support for the latest generation of PCIe 4, which has some notable advantages over its predecessor, PCIe 3. Here’s what you need to know about the next generation of PCIe.


PCIe 3 has been available on a huge swathe of different motherboards since 2010, and continues to be the most populous PCIe port available in 2020. It’s found on 300 and 400-series motherboards for AMD’s first and second generation Ryzen CPUs, as well as on Intel 300-series boards used for its 8th and 9th-gen processors. It’s also found on most boards released over a few years before these chip generations.

PCIe 4 made its debut with AMD’s third-generation Ryzen processors on its 500-series motherboards, specifically with the x570 chipset. As of early 2020, the only motherboards that support PCIe 4 are based on the AMD x570 chipset.

Intel hasn’t made any official commitment to PCIe 4 support on compatible motherboards, though it has released its own PCIe 4 SSDs. Some rumors pointed to Intel debuting PCIe 4 with its 10th-generation Comet Lake CPUs, but that due to problems implementing it, Intel had to nix the feature, according to Toms Hardware. Meanwhile, our own reporting has revealed internal documents that confirm that Intel’s new Xe graphics cards will use PCIe 4.

Motherboards may still technically support it, though, so it may be that when the next-next-generation Rocket Lake CPUs debut in 2021, that existing Comet Lake boards could gain the feature with a chip upgrade.

Other speculation says that Intel may skip PCIe 4 altogether and instead push for the recently standardized PCIe 5 with future CPU generations.


Biostar Z170GT7
Bill Roberson/Digital Trends

The greatest advantage of PCIe 4 over PCIe 3 is in its speed — or overall bandwidth. Like generations of PCIe before it, PCIe 4 doubles its bandwidth over the last-generation, increasing the per-lane bandwidth 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 anything that plugs into a PCIe slot more headroom, but for the most powerful of graphics cards, that’s not really needed just yet. The 2080 Ti, the most powerful mainstream graphics card ever made, doesn’t come close to saturating an x16 PCIe 3 slot, only seeing some bottlenecking on PCIe 3 x8 slots, as TechPowerUp proved in its 2018 testing.

Where this additional bandwidth can be taken advantage of in full is with other kinds of add-in cards. Most namely, storage. Multiple PCIexpress 4.0 NVMe drives can operate in RAID 0 configuration to offer sequential read/write speeds of up to 15GBps.

Extra lanes and compatibility

With little real-world tasks that can take advantage of the full bandwidth of PCIe 4 x16 slots, the major advantage of it, at least in the near future, will be in the reduction in lane requirements for devices and add-in cards. Instead of a 10 Gigabit network card requiring multiple PCIe 3 lanes, it can get away with just a 1x slot. Graphics cards can operate at PCIe 4 x8 speeds, enjoying the same bandwidth as PCIe 3 x16 slots, but with half the lanes used.

Those additional lanes can be freed up for additional devices in larger builds, or allow for faster devices to operate on smaller PCIe slots for more compact systems.

Supporting boards aren’t limited to PCIe 4 devices either. PCIe 4 slots are entirely backwards compatible, meaning that any older-generation PCIe devices, whether it’s first, second, or third generation, will work just fine with PCIe 4.

Editors' Recommendations

Jon Martindale
Jon Martindale is the Evergreen Coordinator for Computing, overseeing a team of writers addressing all the latest how to…
Dell vs. HP: Which laptop brand is best for your needs?
The Dell XPS 13, open on a table in front of a window.

Dell and HP are on our list of the best laptop brands for a reason. In recent years, both of these laptop manufacturers have consistently produced some of the most well-designed machines you can buy. So it’s understandable if you’re shopping for a new laptop, and you’re having trouble deciding between these two huge, highly-rated brands. Both have a lot to offer and it can be overwhelming to sift through all of the cool features, price points, and other factors you might want to consider before purchasing a laptop from either of these manufacturers.

And if you do need help picking the right laptop brand for yourself, you’ve come to the right place. In this comparison guide, we’ll show you everything you need to know about the differences between HP’s best laptops and Dell’s best laptops. Specifically, we’ll go over how they differ in design, their respective features, their price ranges, and which brands are best for certain use cases like school, business, video editing, and gaming.

Read more
Surface Laptop Go 3 vs. Surface Pro 7+: is it an upgrade?
Microsoft Surface Pro 7

The Surface Laptop Go 3 is Microsoft's new affordable Surface laptop, with upgraded hardware and long battery life making it a compelling option for budget laptop buyers in 2023. But for anyone considering an upgrade to a Surface device at around that $800 price, the Surface Pro 7+ still presents an attractive purchase, and it can flip into a tablet when you need it.

That brings to mind the age-old question, of whether newer is automatically better. In this case, it might not be. Let's take a look at the Surface Laptop Go 3 versus Surface Pro 7+, to find out.

Read more
Microsoft Bing and Edge are getting a big DALL-E 3 upgrade
Microsoft Copilot comes to Bing and Edge.

Microsoft Copilot is coming to Bing and Edge Microsoft

You'll soon be hearing more about Microsoft Copilot and Bing Image Creator as these innovative technologies come to Microsoft Edge and Bing. The news of their arrival was delivered at Microsoft's Surface Event, along with several more AI and hardware announcements.

Read more