If you've been shopping for a new motherboard, a new SSD, or a new GPU, you've probably heard about different PCIe versions. PCIe 5.0 is the latest and greatest, but the funny thing is that it still doesn't really matter. There are very few tech products out there that can actually saturate the additional bandwidth of PCIe 4.0, let alone 5.0.

4 GPUs don't even use PCIe 5.0

The Nvidia GeForce RTX 4090 still uses PCIe 4.0

If you have an Nvidia GeForce RTX 4090, you might be surprised to learn that it doesn't even use PCIe 5.0. It's built to 4.0 standards, but will even work in a 3.0 slot. On top of that, you won't even really see any negatives to running it in a 3.0 slot.

Why this is the case is that each PCIe 4.0 lane transfers roughly 2GB/s, whereas PCIe 5.0 transfers roughly 4GB/s per lane. Therefore, a card running in PCIe 4.0 with 16 lanes will manage to transfer 32GB/s in each direction. This is an incredible amount of data, and even running an RTX 4090 in a PCIe 4.0 slot with eight lanes (or a PCIe 3.0 slot with 16 lanes) shows a marginal decrease in performance, to the point that it's not even worth worrying about.

All in all, the biggest reason PCIe 5.0 doesn't matter is that right now, PCIe 3.0 with 16 lanes will give the same amount of bandwidth to your GPU as what many many people get with an eight-lane configuration in PCIe 4.0, which can happen when your motherboard shares PCIe lanes with your M2 SSD.

3 Limited storage benefits

PCIe 5.0 SSDs have drawbacks

If you have a PCIe 5.0 SSD, chances are the incredible read speeds of the likes of 12,000 MB/s caught your eye. However, these eye-watering numbers aren't really practical in the sense that they don't really yield any actual performance gains, as there comes a point where your CPU and GPU are the bottlenecking in being able to process that data.

Plus, PCIe 5.0 SSDs run hot. They use a lot of power, are significantly more expensive, and random access read speeds are more aligned to PCIe 4.0. They're just not worth picking up really, and you might even need to pick up a heatsink for your PCIe 5.0 M2 SSD in some cases.

2 PCIe seems to advance much faster than the technology that can use it does

Not really a problem, but still something to consider

PCIe as a standard has advanced leaps and bounds over years and years, but it's clear that the benefits aren't really being used in hardware released today. Even when it is, like in SSDs, there are drawbacks that make the previous generation considerably enticing. For example, those heat concerns previously mentioned mean that unless you have the right systems in place to cool your SSDs, you risk overheating them if they're using PCIe 5.0.

On top of that, the power requirements of PCIe 5.0 are higher than 4.0. Not by a significant margin of course, but it's yet another drawback of upgrading for little gain.

1 PCIe advancements benefit servers a lot sooner than PCs

Enterprise is where all the money is

If you think the 24 usable lanes for PCIe 5.0 in modern CPUs like the AMD Ryzen 7 9800X3D or the Intel Core Ultra 9 285K was a lot, try 128 lanes. AMD's EPYC 9005 Series processors have support for 128 PCIe 5.0 lanes in a single-socket configuration, and that goes to 160 in a dual-socket configuration. And you best believe the reason for so many PCIe 5.0 lanes is that companies will actually make use of them.

For example, Compute Express Link (CXL) devices like SmartNICs and accelerators will actually make use of PCIe 5.0 lanes. NIC stands for Network Interface Card, and a SmartNIC can do things like load balancing and telemetry, and can even manage things like a firewall, offloading some processing from the CPU. Nvidia's latest ConnectX-7 SmartNICs can accelerate custom software-defined networking stacks, provide robust security features like in-line encryption and decryption, and enable firewalls along with a hardware root of trust for secure boot processes.

On top of that, they support essential security protocols such as TLS, IP Security (IPsec), and MAC Security (MACsec). On the storage front, they manage protocols like RoCE, GPUDirect Storage, NVMe, and TCP. They can also improve performance in virtualized data centers, as they offer support for Single-Root I/O Virtualization (SR-IOV) and virtual switching and routing capabilities.