Fortnite

Fortnite is notoriously sensitive to both CPU and GPU, and this pairing of a six-core Intel Core i5-9400 with the high-end NVIDIA GeForce RTX 3080 creates a fascinating bottleneck dynamic. The benchmark data shows a system that delivers extremely high frame rates at lower resolutions but struggles to maintain a smooth 60 FPS at 4K Ultra. The performance curve is steep, and the limiting factor shifts dramatically depending on the resolution and settings you choose.

Resolution Scaling

The frame rate drop from 1080p to 4K is severe and tells a clear story about where the performance ceiling lies. At 1080p Low, the combo produces 288.8 FPS, but at 1440p Low, it falls to 202.3 FPS, and at 4K Low, it drops to 109.1 FPS. This represents a 62% reduction in frame rate from 1080p to 4K at Low settings. The scaling is similar at High settings: 174.7 FPS at 1080p, 110 FPS at 1440p, and 62 FPS at 4K.

The pattern indicates that at 1080p, the RTX 3080 is largely held back by the i5-9400’s six cores and six threads. The GPU is capable of much higher output, but the CPU cannot feed it fast enough. As resolution increases, the load shifts to the GPU, and the RTX 3080 begins to show its true power. The fact that 4K Low (109.1 FPS) is still faster than 1080p Ultra (114.4 FPS) highlights how much the CPU limits the system at lower settings. The 4K Ultra result of 37 FPS is the only point where the GPU is fully saturated, and it is clearly the bottleneck there.

The delta between Low and Ultra settings at each resolution is also telling. At 1080p, the gap between Low (288.8 FPS) and Ultra (114.4 FPS) is 174.4 FPS. At 4K, the gap narrows to 72.1 FPS between Low (109.1 FPS) and Ultra (37 FPS). This compression at higher resolutions suggests that the GPU’s raw compute becomes the dominant factor, while the CPU’s role in frame pacing diminishes.

CPU Role

The Intel Core i5-9400 is a Coffee Lake Refresh part with six cores and six threads, a base clock of 2.90 GHz, and a boost clock of 4.10 GHz. It has 9 MB of shared L3 cache and supports DDR4 memory with a dual-channel bus. The data shows this CPU sits at the 50th percentile among all tested CPUs, with a Cinebench R23 multicore score of 7969 and a single-core score of 1125. Its average benchmark score is 2305, which is nearly identical to the Intel Core i3-10305 (2300, 0.2% slower) and the Intel Core i3-1125G4 (2299, 0.2% slower). It is 0.6% slower than the Intel Core i7-8809G (2319).

In Fortnite, the CPU’s six threads are a limiting factor at 1080p. The game’s engine can utilize multiple cores, but the i5-9400 lacks the multi-threading capabilities of a hyper-threaded chip. The benchmark results show that at 1080p Low, the system achieves 288.8 FPS, but this is likely near the CPU’s maximum frame generation capacity. The RTX 3080 is far more powerful, as indicated by its 80th percentile ranking among all GPUs and its 3DMark Steel Nomad score of 4407. The CPU is simply not able to keep up with the GPU’s potential at lower resolutions.

The boost clock of 4.10 GHz helps in single-threaded tasks, which is why the single-core Cinebench score is respectable. However, Fortnite is not purely single-threaded, and the lack of additional threads becomes apparent when comparing to higher-core-count CPUs. The data suggests that for competitive play at high refresh rates, this CPU will hold back the RTX 3080. For a more balanced experience, you would need a CPU with higher multi-threaded performance.

FAQ

Q: What is the average FPS at 1080p with High settings?

A: The system achieves 174.7 FPS at 1920x1080 with High settings, which is sufficient for a high-refresh-rate monitor.

Q: Can this combo handle 4K gaming?

A: It can, but only with compromises. At 4K Low, the system produces 109.1 FPS, while 4K Ultra drops to 37 FPS. Medium settings at 4K yield 76.9 FPS, which is playable but not ideal for fast-paced action.

Q: How does the CPU compare to its nearest rivals?

A: The i5-9400 has an average benchmark score of 2305, making it 0.2% faster than the Intel Core i3-10305 (2300) and 0.4% faster than the Intel Xeon E-2134 (2295). It is 0.6% slower than the Intel Core i7-8809G (2319).

Q: Is the RTX 3080 a good match for this CPU?

A: The data suggests a significant bottleneck at 1080p. The GPU is far more capable than the CPU can feed, but at 4K, the balance shifts and the GPU becomes the limiting factor. The RTX 3080’s 10 GB of GDDR6X memory and 760.3 GB/s bandwidth are well-suited for high-resolution textures.

Q: What is the best settings preset for a 1440p monitor?

A: At 2560x1440, High settings produce 110 FPS, while Medium produces 142.7 FPS. Low settings yield 202.3 FPS. For a balance of visual quality and performance, Medium or High is recommended.

Q: How does the GPU rank among all tested GPUs?

A: The RTX 3080 is in the 80th percentile of all GPUs, with an average benchmark score of 35787. It is 0.2% faster than the AMD Radeon Pro Duo (35860) and 0.4% faster than the AMD Radeon 880M (35646).

How This Combo Ranks

This specific combination of the Intel Core i5-9400 and NVIDIA GeForce RTX 3080 ranks 500th out of 1564 tested combos in Fortnite. This places it in the top third of all configurations, which is respectable given the CPU’s age and the GPU’s high-end positioning. The rank reflects the system’s ability to produce high frame rates at 1080p and 1440p, but the CPU bottleneck prevents it from achieving the top-tier placement that the GPU alone would suggest.

The ranking is likely dragged down by the CPU’s performance at lower resolutions. The RTX 3080 is capable of much higher frame rates, as evidenced by its GPU benchmarks and 80th percentile ranking. If paired with a stronger CPU, this GPU would likely rank much higher. The 500th position out of 1564 combos indicates that while this is a functional system for Fortnite, it is not an optimal pairing. The data shows that the i5-9400 is the primary constraint, and the combo’s rank reflects this imbalance.

GPU Role

The NVIDIA GeForce RTX 3080 is a high-end Ampere architecture GPU with 10 GB of GDDR6X memory on a 320-bit bus, providing 760.3 GB/s of bandwidth. It has 8704 shading units, 272 texture mapping units, and 96 raster output units. The GPU’s base clock is 1440 MHz with a boost clock of 1710 MHz, and it features 68 RT cores and 272 tensor cores. Its FP32 performance is 29.77 TFLOPS. The GPU is built on an 8 nm process with 28,300 million transistors on a 628 mm² die.

In Fortnite, the GPU’s role becomes apparent at higher resolutions. At 4K Ultra, the system drops to 37 FPS, indicating that the GPU is fully saturated. The 10 GB of VRAM is sufficient for Fortnite’s textures, even at 4K, and the 760.3 GB/s bandwidth ensures fast data transfer. The GPU’s pixel rate of 164.2 GPixel/s and texture rate of 465.1 GTexel/s are more than adequate for this game. The benchmark data shows that the RTX 3080 can easily handle 1440p High at 110 FPS, but the CPU limits it to 174.7 FPS at 1080p High.

The GPU’s PassMark G3D score is 25086, and its 3DMark Steel Nomad score is 4407. These numbers indicate a very powerful graphics card. The GPU’s performance in Fortnite is strong, but the i5-9400 prevents it from reaching its full potential at lower resolutions. At 4K, the GPU is the limiting factor, and the system’s performance is more indicative of the RTX 3080’s capabilities.

Measured FPS Breakdown

The measured FPS data provides a complete picture of the system’s performance across resolutions and settings. At 1920x1080, the system achieves 288.8 FPS on Low, 228.7 FPS on Medium, 174.7 FPS on High, and 114.4 FPS on Ultra. These numbers show a clear progression, with Low settings providing nearly 200 FPS more than Ultra.

At 2560x1440, the frame rates are lower but still highly playable. Low settings produce 202.3 FPS, Medium produces 142.7 FPS, High produces 110 FPS, and Ultra produces 74.7 FPS. The 1440p results are more balanced, with a smaller gap between Low and Ultra (127.6 FPS difference).

At 3840x2160, the system’s performance drops significantly. Low settings yield 109.1 FPS, Medium yields 76.9 FPS, High yields 62 FPS, and Ultra drops to 37 FPS. The 4K results show that the RTX 3080 is the primary bottleneck, as the frame rates are much lower than at 1440p, and the gap between Low and Ultra is only 72.1 FPS.

The data indicates that for competitive play, 1080p Low or Medium is ideal, with frame rates well above 200 FPS. For casual play at 1440p, High settings provide a good balance at 110 FPS. At 4K, Medium settings are the highest viable option, with 76.9 FPS, while Ultra is only suitable for slow-paced scenarios. The measured FPS values confirm that this system is best used at 1080p or 1440p, with the CPU limiting performance at lower resolutions and the GPU limiting performance at 4K.