Does PCIe 4.0 Matter for Gaming? Yes, But Only Marginally Right Now.
PCI Express (PCIe) provides the interface and bandwidth for components like your graphics card to communicate with the rest of the system. With twice the maximum bandwidth of PCIe 3.0, PCIe 4.0 sounds like an obvious upgrade. But in reality, it currently only improves gaming performance by single-digit percentages. Let‘s fully break down when and why PCIe 4.0 matters for gaming.
What is PCIe and How Do The Versions Compare?
PCI Express is like the highway that data travels on between components in your PC. It connects crucial parts like your graphics card, NVMe SSDs, WiFi cards, USB ports, and more.
PCIe transfers data via lanes – each PCIe lane provides a certain bandwidth capacity:
- PCIe 3.0 – 32 GB/s total per x16 slot, 8 GT/s transfer rate per lane
- PCIe 4.0 – 64 GB/s total per x16 slot, 16 GT/s per lane
This means PCIe 4.0 has double the maximum theoretical bandwidth compared to PCIe 3.0.
Here‘s a quick diagram to visualize how much more data can travel on the PCIe 4.0 "highway":
| Version | Lanes | Bandwidth Per Lane | Total Bandwidth (x16 slot) |
|---|---|---|---|
| PCIe 3.0 | 16 | 8 GT/s | 32 GB/s |
| PCIe 4.0 | 16 | 16 GT/s | 64 GB/s |
The versions are fully backwards and forwards compatible too. A PCIe 4.0 graphics card will work in a PCIe 3.0 motherboard slot, for example. The card will simply run at PCIe 3.0 speeds.
Why Would Extra Bandwidth Help Gaming Performance?
Higher resolutions means there are quite literally more pixels that need to be rendered and pushed to your display.
- 1080p has around 2 million pixels
- 1440p has 3.7 million pixels
- 4K has a whopping 8.3 million pixels!
So higher resolution gaming requires transferring much more visual data from the GPU through the PCIe interface to your monitor. More bandwidth here allows the GPU to breathe and stretch its legs better.
High-end GPUs are also starting to get powerful enough to nearly saturate or max out a PCIe 3.0 x16 connection. The RTX 3090 hits over 350 GB/s memory bandwidth, closing in on the PCIe 3.0 limit.
PCIe 4.0 removes this bottleneck entirely, allowing today‘s top-tier cards to fully utilize their hardware capabilities.
Real-World Gaming Benchmarks – PCIe 4.0 Provides Minimal Gains
Synthetic benchmarks that test PCIe bandwidth show clear differences between PCIe 3.0 and 4.0 speeds. But for actual games, PCIe 4.0 surprisingly doesn‘t offer much improvement:
- At 1080p resolution, PCIe 4.0 was 1% faster than PCIe 3.0 on average across many games.
- At 1440p, it provided a 1.5% boost.
- And at 4K resolution is where PCIe 4.0 helped the most, but still only by 2.8% on average.
These are averages across many game titles too. For some games, there was no measurable difference in FPS between PCIe generations.
Here are benchmark results in some popular games at 4K resolution specifically:
| Game | PCIe 3.0 FPS | PCIe 4.0 FPS | % Improvement |
|---|---|---|---|
| Red Dead Redemption 2 | 71 | 73 | 2.8% |
| Horizon Zero Dawn | 87 | 89 | 2.3% |
| Assassin‘s Creed Valhalla | 71 | 73 | 2.8% |
| Cyberpunk 2077 | 64 | 66 | 3.1% |
Upgrading to PCIe 4.0 clearly provides very little extra performance in most games right now. The GPU is still the primary limitation rather than PCIe bandwidth.
When Does PCIe 4.0 Provide More Noticeable Gains?
While PCIe 4.0 currently only improves average FPS by low single-digit percentages, there are some cases where it has more of an impact:
- High-end GPUs – Upgrading to the RTX 3090 shows larger gains, since it can finally stretch past PCIe 3.0‘s limits when paired with a PCIe 4.0 motherboard and components.
- 4K gaming – Higher resolution appears to stress the interface more. PCIe 4.0 helps most at 4K compared to 1440p or 1080p.
- Multiple PCIe 4.0 NVMe SSDs – Having multiple high-speed SSDs benefits from the extra bandwidth for simultaneous access.
Mid-range cards like the RTX 3060 Ti at 1440p or lower resolutions basically see no improvement with PCIe 4.0 over 3.0. The GPU hits its limit first.
What Does The Future Hold for PCIe Bandwidth Needs?
While current real-world gaming gains are small, PCIe 4.0 does provide much more headroom for next-generation GPUs and games to scale performance without being limited by PCIe slot bandwidth.
Nvidia‘s new RTX 40 series cards are rumored to nearly double the power consumption of the 30 series. We‘re also seeing GPU memory bandwidth increase over 500 GB/s. 8K gaming could become more viable as well.
These advancing technologies will inevitably require more PCIe bandwidth to reach their full potential.
Upgrading to PCIe 4.0 now helps future proof your system for tomorrow‘s GPU and game performance needs. You likely won‘t need to upgrade the motherboard again just for PCIe slot bandwidth reasons.
PCIe 4.0 – Modest Gains Today, But Valuable Future Proofing
While PCIe 4.0 currently only improves gaming performance marginally over PCIe 3.0, the doubled bandwidth headroom does allow much more room for next-gen GPUs and games to stretch their legs as graphics demands increase.
If building a new high-end gaming PC, upgrading to PCIe 4.0 is recommended for future proofing. For mid-range systems, PCIe 3.0 remains completely sufficient for today‘s GPUs.
Evaluate if the extra cost of PCIe 4.0 components is worthwhile for your specific build and use case. For most, sticking with PCIe 3.0 is fine, but upgrading to 4.0 makes your system ready for the future of gaming as bandwidth needs evolve.