Is PCIe 4.0 SSD Better Than 3.0 for Gaming?

PCI Express (PCIe) is an interface standard used by many components in a modern gaming PC, including the graphics card, SSD storage, and CPU. PCIe 4.0 is the newest generation and offers double the bandwidth of the previous PCIe 3.0 standard. But is this speed boost worthwhile for gaming workloads? Let‘s dig into the details.

What is PCIe?

PCIe is a high-speed serial connection that allows different components in a system to communicate. It works through "lanes" that carry data in both directions. More lanes means more total bandwidth. The current PCIe generations have the following per-lane bandwidth:

• PCIe 1.0 – 250 MB/s (2 Gbps)
• PCIe 2.0 – 500 MB/s (4 Gbps)
• PCIe 3.0 – 1 GB/s (8 Gbps)
• PCIe 4.0 – 2 GB/s (16 Gbps)

For graphics cards and SSDs, the standard configuration is a x16 slot, which combines 16 lanes for peak throughput. A PCIe 4.0 x16 slot can transfer 32 GB/s total, while PCIe 3.0 x16 manages 16 GB/s.

There are also smaller x1, x4, and x8 slots for peripherals like sound cards, WiFi adapters, and secondary storage. The "x" refers to the number of lanes.

Why PCIe Speed Matters for SSDs

SSD storage was previously bottlenecked by the SATA interface, which maxes out around 550 MB/s. Leading SSDs can now achieve sequential read/write speeds of 3,000 to 7,000 MB/s, so they need a faster connection.

That‘s where PCIe comes in. By switching to a direct PCIe connection, NVMe SSDs can fully utilize their capabilities. The increased bandwidth of PCIe 4.0 further reduces any interface bottlenecks.

For example, the Samsung 980 Pro PCIe 4.0 SSD has sequential read/write speeds over 6,000/5,000 MB/s. The equivalent 970 Evo Plus PCIe 3.0 model is around 3,500/3,300 MB/s.

PCIe Bandwidth for Graphics Cards

Modern GPUs are very powerful, but most can‘t come close to saturating a PCIe 3.0 x16 slot, let alone 4.0. Nvidia‘s flagship RTX 3090 hits peak transfer rates around 6,000-8,000 MB/s, while AMD‘s RX 6900 XT manages 4,000-6,000 MB/s.

There are a few exceptions like the 3090 Ti and RX 6950 XT that can slightly exceed PCIe 3.0 x16 bandwidth for brief bursts. However, these frames represent a fraction of a percent of total playtime.

Plus, game traffic is not 100% sequential transfers. Real-world bandwidth is reduced by latency, protocol overhead, and simultaneous reads/writes going in different directions.

Overall, PCIe 4.0 does not improve gaming performance meaningfully over PCIe 3.0 with current high-end GPUs. Supporting evidence continues to grow from controlled testing as well as real user experiences.

PCIe Version Compatibility

An important detail about PCIe is backwards and forwards compatibility. This means that PCIe 4.0 graphics cards and SSDs will work just fine in PCIe 3.0 motherboards and slots.

Likewise, you can use older PCIe 3.0 or 2.0 components in a PCIe 4.0 system without issues. The device will simply run at the max speed its spec allows.

For example, Nvidia‘s RTX 3000 and AMD‘s RX 6000 graphics card series have PCIe 4.0 support. But you can utilize them in a PCIe 3.0 system and only lose at most a few percentage points of performance.

When PCIe 4.0 Can Improve Game Loading

Faster NVMe SSDs with PCIe 4.0 can help reduce initial game load times, since storage speed has a major impact here. However, for gaming specifically, PCIe 3.0 SSDs are already plenty quick.

Upgrading from a SATA SSD or hard drive to any quality NVMe drive will deliver much more noticeable jumps in load times. The difference between PCIe 3.0 and PCIe 4.0 NVMe SSDs is usually just a few seconds or less.

As you can see from the table, switching to a good NVMe SSD over SATA provides the biggest improvement. PCIe 4.0 shaves off a couple extra seconds over an already fast PCIe 3.0 SSD.

PCIe 4.0 Benefits for Content Creation

While PCIe 4.0 delivers minimal gains for gaming, the doubled bandwidth can make a more substantial impact on professional workloads like:

• 4K/8K video editing
• 3D rendering and CAD
• Data analytics
• Software development and compiling
• Database access
• Virtualization

Creators constantly transferring large files or assets can take full advantage of the extra speed provided by both PCIe 4.0 NVMe SSDs and faster GPUs. For these users, upgrading to PCIe 4.0 is a worthwhile investment.

PCIe 4.0 and DirectStorage API

Microsoft‘s new DirectStorage API for Windows is built to leverage the incredible speeds of PCIe 4.0 NVMe SSDs. It provides a more direct path between the SSD and GPU that bypasses the CPU for decompression and IO handling.

This has the potential to significantly reduce load times and stream assets seamlessly in real-time for detailed open worlds. It‘s a next-generation storage technology that actually benefits from PCIe 4.0 bandwidth.

However, DirectStorage is not yet available for most games. Support still needs to be added at the engine level and properly optimized per title. It will take at least a few more years to become commonplace.

Upgrade Considerations for PCIe 4.0

To utilize PCIe 4.0 requires a compatible CPU and motherboard. For AMD, that means an X570, B550, or newer board and Ryzen 3000 processor or above. Intel offers PCIe 4.0 on Z690 boards and 12th Gen Alder Lake CPUs.

Upgrading your motherboard is no small decision, especially if it requires a new CPU and RAM as well. You‘ll really want to consider if you need PCIe 4.0 right now and what benefits it will provide for your uses.

For gaming, PCIe 4.0 is not a clear win currently. The faster interface does little to increase FPS. Opting for PCIe 3.0 components can save you money with minimal performance loss.

However, if you are a content creator using assets that can take advantage of the bandwidth, or want your system ready for DirectStorage, the added speed of PCIe 4.0 starts to make more sense.

PCIe 4.0 Gaming Performance

Here is a summary of PCIe 4.0 performance gains seen in controlled gaming benchmarks from the past couple years:

• At 4K resolution, average FPS between PCIe 4.0 and PCIe 3.0 graphics cards is within 1-2% across a suite of games. (Gamers Nexus, October 2020)

• The RX 6900 XT saw a 1.8% higher average FPS score in 3DMark Time Spy Extreme with a PCIe 4.0 vs 3.0 system. (Tom‘s Hardware, December 2020)

• Hitman 3 gained only 2% higher average FPS with an RTX 3090 in PCIe 4.0. Most games showed an improvement of 0-1%. (TechPowerUp, January 2021)

• Running Assassins Creed: Valhalla on the PCIe 3.0 RTX 3080 saw just a 3.7% drop in average FPS at 4K compared to PCIe 4.0. (PC Gamer, February 2021)

• Call of Duty: Warzone measured the same average and 1% low FPS using an RTX 3080 on either PCIe 3.0 or 4.0 with an Intel Core i9-12900K. (Tom‘s Hardware, February 2022)

While more bandwidth can show minor performance gains in best case scenarios, overall PCIe 4.0 does not tangibly improve frame rates over PCIe 3.0. Any difference falls within the margin of error during real gameplay.

Is a PCIe 4.0 SSD Worth It for Gaming?

Here is a quick summary on whether a PCIe 4.0 SSD is recommended for a gaming PC:

• A PCIe 4.0 SSD provides minimal load time benefits over a PCIe 3.0 SSD, usually just a few seconds.

• The much larger leap comes from switching to any NVMe SSD from a SATA SSD or hard drive.

• PCIe 4.0 SSDs currently carry a price premium over PCIe 3.0 models with similar performance and endurance.

• Most GPUs cannot saturate a PCIe 3.0 x16 connection, so PCIe 4.0 offers no actual performance advantage.

• PCIe 3.0 SSDs and GPUs will work without issue in PCIe 4.0 motherboards and slots.

For pure gaming usage, a PCIe 4.0 SSD is hard to justify currently. There are only minor load time decreases, and no change to actual FPS. The better value is sticking with a quality PCIe 3.0 SSD until 4.0 drive prices fall closer to MSRP.

However, if you also use your system for content creation and productivity tasks that leverage the extra bandwidth, the cutting-edge speeds of PCIe 4.0 SSDs make more sense.

Conclusion

While PCIe 4.0 delivers impressive gains in raw throughput over PCIe 3.0, for real world gaming usage, the impact is minor at this time. There is no meaningful improvement to FPS, and only small reductions in load times for a PCIe 4.0 NVMe SSD or graphics card.

Given the lack of substantial gaming benefits, upgrading to PCIe 4.0 specifically is hard to recommend now for most gamers. The better upgrade path focuses on the GPU, CPU, resolution, and quality/speed of the PCIe 3.0 SSD.

However, if you utilize your system for content creation as well, have future interest in leveraging DirectStorage, or simply want the latest technology, PCIe 4.0 and its doubled bandwidth can certainly excel there.