PCI Express, or PCIe, continues to be a crucial part of computing devices as one of the primary interconnects that allows you to connect various peripherals including GPUs, SSDs, capture cards, and more to your computing device. In 2021, devices using the newest version of PCIe (version 5.0) came out. But what is PCIe 5.0, and how is it different from Gen 4? Also, do you really need to upgrade from PCIe Gen 4? There's a lot to unpack when it comes to PCI Express 5.0, so here's everything you need to know about the new standard.
What is PCIe 5.0?
PCIe 5.0 or Gen 5 is essentially just a new standard of PCIe that brings double the amount of data transfer compared to PCIe 4.0 or Gen 4. This enables higher performance on pretty much every kind of device, but especially SSDs and (to a certain extent) GPUs. Seeing a doubling in bandwidth is actually pretty regular and happens about every four years, but on the other hand it's also impressive to see a new generation of devices with even more room to boost performance.
At the time of writing, AMD's AM5 motherboards and Intel's LGA 1700 motherboards all support PCIe 5.0 to varying degrees. Meanwhile, very few PCIe 5.0 devices have launched. The first PCIe 5.0 SSDs have just launched at the time of writing, but PCIe 5.0 GPUs aren't expected until the next generation, which could be as late as 2024. In order to take advantage of PCIe 5.0, both ends of the connection need to support it; if you have PCIe 5.0 on your motherboard but PCIe 4.0 on your SSD (or vice versa), the SSD runs at PCIe 4.0 speeds.
As a side note, you've probably heard about PCIe 5.0 PSUs, and you might be wondering what that even means since PSUs deliver power, and have nothing to do with actual data transfer. The PCIe 5.0 specification and guidelines for devices that use it also defines how new ATX 3.0 PSUs and the new 16-pin 12VHPWR cable are supposed to work. Basically, all you need to know is that a PCIe 5.0 PSU is not necessary to power a PCIe 5.0 device; what the PCIe 5.0 branding really means is that it has a native 16-pin connector.
PCIe Gen 5 vs PCIe Gen 4
PCIe Gen 4 is the current standard that's supported by a majority of processors and motherboards out there, and while it was impressive when it came out, we're starting to hit the point where it's bottlenecking performance. For example, most SSDs come in the M.2 NVMe form factor, which means they only have access to four lanes. At PCIe 4.0 speeds, that's 8GB/s of constant data transfer, and the fastest SSDs you can buy are approaching that 8GB/s limit. A PCIe 5.0 SSD has double that amount to spread its legs: 16GB/s. A PCIe 5.0 device with 32 lanes has 128GB/s of bandwidth, and that's much faster than devices using older versions of PCIe.
|PCIe 1.0 x32||8GB/s||2.5GT/s||2.5GHz|
|PCIe 2.0 x32||16GB/s||5GT/s||5GHz|
|PCIe 3.0 x32||32GB/s||8GT/s||8GHz|
|PCIe 4.0 x32||64GB/s||16GT/s||16GHz|
|PCIe 5.0 x32||128GB/s||32GT/s||32GHz|
So, should you upgrade to PCIe 5.0 components? Ultimately, a product is judged by what it can actually do rather than what it can theoretically do. It's undeniable that PCIe 5.0 needs to exist in order for faster devices to get developed, but just having PCIe 5.0 doesn't make a GPU or SSD immediately better. That's especially true for GPUs, and it's unlikely that PCIe 5.0 will be a game changer for graphics cards since they usually come with more than enough bandwidth already.
However, the hype for PCIe 5.0 SSD is definitely justified, as the increased bandwidth enables higher transfer speeds in sequential reads and writes, which is what's important when dealing with large files. In a review by PCWorld, Gigabyte's Aorus Gen5 10000 was multiple gigabytes per second faster than Western Digital's SN850X, one of the fastest PCIe 4.0 SSDs. The playing field is more even when considering random reads and writes (where the Aorus Gen5 did poorly), which are rarely ever bottlenecked by the speed of the PCIe data link.
Perhaps the biggest consideration in upgrading to PCIe 5.0 is the fact that you need a compatible motherboard, and only AMD 600 series motherboards (for Ryzen 7000 processors) and Intel 600 and 700 series boards (for 12th-gen and 13th-gen CPUs) boards support PCIe 5.0. Upgrading your motherboard, CPU, and even memory might be necessary to be able to use PCIe 5.0 devices, which is quite expensive considering this is what you need just to get support. There's also the fact that different motherboards have differing levels of PCIe 5.0 support, and boards with more PCIe 5.0 slots are more expensive.
Staying on a platform with only PCIe 4.0 or even 3.0 support is a viable option. Older SSDs are still pretty fast and they're also perpetually on sale at relatively low prices, while PCIe 5.0 SSDs will almost certainly be more expensive per gigabyte when they finally come out. Besides, you can always upgrade later when the ecosystem is more developed and the components are cheaper.
PCIe 5.0 Release Date
Although the PCI Express 5 standard was released back in 2019, we still don't have many PCIe 5.0 capable devices on the market; it takes time for these things to come out. Thankfully, the motherboards that have PCIe 5.0 support have come out before components like SSDs and GPUs, which means you can go out and build a brand-new PC and plug a Gen 5 device in without issue.
However, PCIe 4.0 isn't going away quite yet, mainly because it costs more to add PCIe 5.0 support to electronics. Even the highest-end motherboards in the current generation aren't 100% PCIe 5.0, and most midrange boards mostly use PCIe 4.0. It will be some time before PCIe 5.0 becomes the norm, and once it does we'll probably see PCIe 6.0 devices popping up, since the specification has actually been out for a year already.
Speaking of PCIe 6.0, you might be wondering when that's coming out. If the schedule for PCIe 5.0 is any indication, we should expect PCIe 6.0 to make its debut around 2025 or 2026. This probably means AM5 motherboards will never see PCIe 6.0 except perhaps on its very last chipset. As for Intel, it's possible that PCIe 6.0 will be introduced on the company's next socket (which will support 14th Gen Meteor Lake CPUs) but it's more likely that Intel will wait for the socket after that if we assume Intel keeping up with its yearly cadence for new CPUs and motherboards.
Q: What is PCI Express?
Peripheral Component Interconnect Express is essentially an interface that connects high-speed components to a computing device. Every motherboard has a varying amount of PCIe slots that are used to connect PCIe peripherals like GPUs, SSDs, capture cards, etc. PCIe 1.0 was introduced in 2003, eventually replacing AGP as the most popular interconnect for GPUs. In 2011, PCIe became the foundation of the Non-Volatile Memory Express (NVMe) interface, which is primarily used for SSDs. PCIe 5.0 marks the fifth full generation of the PCIe interconnect.
Q: What are the different PCIe slot configurations?
PCIe slots come in different sizes: x1, x4, x8, x16, and very rarely x32. The number after the "x" tells you how many lanes that PCIe slot has. For example, a PCIe x4 slot has 4 lanes.
Q: Can I insert an old PCIe 4.0 compatible peripheral into a Gen 5 slot?
Yes, PCIe 5 slots are backward compatible which means you can insert older-generation peripherals into the new slot. However, the connection will run at the speed of the slowest device, so a PCIe 4.0 SSD can only run at PCIe 4.0 even in a slot that supports PCIe 5.0.
Q: What is the maximum bandwidth of PCIe 5.0?
PCIe 5.0 has a bandwidth of 3.94 gigabytes per second for each lane. On a device with 16 lanes (like a GPU) that's roughly 63GB/s, and on a device with 4 lanes (like an SSD) that's about 16GB/s.