With new technology developed by PCI SIG (Peripheral Component Interconnect Special Interest Group), more recent generations of previous designs are making their way into the market, enabling bandwidth speeds never seen before. Designated in 2017, PCIe 4.0 is set up to double the bandwidth over the previous PCIe 3.0 and accommodate different devices ranging from 1x, 4x, 8x, and 16x sets of pathways to interact with the rest of a PC.
PCIe Gen 4 or PCIe 4.0 majorly matters for workloads and specific workstation applications focused on generating as much data to throughput. Sticking with PCIe Gen 3 is acceptable for any previous series of GPUs or accessories due to the bandwidth capabilities for gaming. Looking forward to the next generation of hardware is where PCIe Gen 4 and the anticipated Gen 5 will shine.
This article covers when to switch to PCIe 4.0 and your system's needs, depending on the hardware used.
What Is PCIe 4.0?
PCIe (Peripheral Component Interchange Express) is a standard that has dominated the motherboard industry for 20 years. PCIe 4.0 is the fourth iteration in this series of hardware. It has made its way to motherboard manufacturers to be distributed among the 600 and 700 series of motherboards for Intel and AMD CPUs from 2019 onward.
PCIe 4.0, on paper, is twice the speed of PCIe 3.0, with double the bandwidth available in its slots. The highest bandwidth available on PCIe 4.0 motherboards is 16x or 16 lanes with variable data rates depending on the supported hardware generation, down to 8x, 4x, 2x, and 1x for speed and bandwidth.
Benefits of PCIe 4.0
Besides faster speeds, there are multiple benefits to PCIe 4.0 introducing itself into the newest motherboards. Due to the increased bandwidth is often seen with new iterations of hardware supporting optimizations like AMD's Infinity fabric, focusing on utilizing as much cache and, by relation, VRAM capability as possible.
Here is a graph outlining the throughput utilization or amount of data being sent of every PCIe generation for the last 20 years.
Gen 4 doubles every aspect of the previous generation; in addition, there is PCIe Gen 5 which is still in its development phase and seeks to double the bandwidth of Gen 4.
Does PCIe 4.0 Improve GPU Performance?
PCIe 4.0 improves the throughput or data transferred between the GPU and the rest of the system. The current generation of hardware on the market utilizes PCIe 4.0 as the gold standard for data transfers and processing speed for GPUs and NVMes. Further generations of cards have to wait for PCIe 5.0 for better data transfer rates once we know more about them.
Does PCIe Gen 4 Matter For Gaming?
In terms of gaming, PCIe 4.0 and PCIe 3.0 provide the same performance despite the bandwidth capabilities of each generation. So why all the excitement?
PCIe 3.0 vs. PCIe 4.0
Disregarding PCIe 5.0, Let's look at the advantages between Gen 3 and Gen 4, which have made the last two generations of cards perform as well as they have.
The PCIe slot physically has remained the same since 2003; the significant additions over the years have been the number of lanes or contacts, allowing GPUs or other PCIe accessories to interact with the rest of the system.
Some older versions of the PCIe slot may not have the all-knowable motherboard clip at the end of the slot to secure the GPU or accessory, which inadvertently came with later motherboards developed on the standard.
Doubling the speed on PCIe comes with doubling the contact points or changing the method of communication; within a PCIe bracket, there are a set amount of contact points (160 gold contacts for 16x devices, to be precise) to transfer data over a set bandwidth dependent on the motherboard slot and hardware itself.
Using the same form factor of the slot with more bandwidth availability, has enabled motherboards to be backwards compatible with previous generations of GPUs and accessories. Requiring only a mode in the BIOS to be activated, any GPU from Gen. 2.0 upwards should be backwards compatible with any newly released PCIe standard.
Typically the price of PCIe 3.0 motherboards compared to Gen 4 motherboards are marginally cheaper due to Gen 3 being around longer than Gen 4. Getting a PCIe 4.0 motherboard may be advantageous for the next generation of PC hardware, depending on your upgrading journey.
Overall, Does PCIe 4.0 Make a Difference?
If you plan to buy an RTX 40 series card (especially the RTX 4090), you should upgrade to a motherboard with at least PCIe 4.0 capabilities to take advantage of the total bandwidth transfer of that GPU.
Typically for gaming, the results will be the same (a 1 to 2% difference at most) however, for workload optimization, you may see some advantages of PCIe 4.0 over 3.0 in specific use cases.
Is PCIe 4.0 Worth It?
Depending on who you talk to, PCIe 4.0 is worth it in the interim for the anticipated PCIe 5.0 release, likely in Q4 2023. Although the hardware community expected PCIe 5.0 being used in the latest RTX 40 series launch, Nvidia has put that rumor down. Instead, it has gone with PCIe 4.0 due to the bandwidth available just meeting the RTX 4090s abilities in data transfer.
Summary of PCIe 4.0 for Gaming on PC
Whether you are looking to prepare for the RTX 40 series of cards or the anticipated RTX 50 series, going with PCIe 4.0 is a great decision when looking ahead at your system's future. PCIe 3.0 has yet to be fully supported, but the transition has slowly begun with the advent of PCIe 5.0.
At Apex gaming PCs, we offer both PCIe4.0 and 3.0 motherboards with the ability for backwards compatibility and multiple supported accessories like vertical mounted ribbon cables, backward compatible GPUs, and other assortments of display outputs and accessories. Feel free to look at our custom builder, which offers additional expansion cards that can fit on a motherboard with multiple PCIe lanes. Whatever your motherboard needs, we hope to be of service at Apex!
Written By William Wilson
Photo Credits: Pavan Bhakta & Synopsis Blog