Rust

The Intel Core i5-9400 paired with the NVIDIA GeForce RTX 3080 produces a surprisingly balanced but ultimately GPU-bound experience in Rust, according to the measured data. The combination ranks 652nd out of 1,717 tested combos, placing it in the upper 38th percentile of all systems. This is a notable position given that the CPU sits at exactly the 50th percentile of all processors, while the GPU ranks in the 80th percentile. The data suggests that Rust’s engine can leverage the RTX 3080’s substantial compute resources effectively, though the six-core i5-9400 occasionally acts as a ceiling at lower resolutions and settings.

FAQ

Q: What is the best resolution for this combo in Rust?

A: The data shows the most consistent performance at 1920x1080, where even Ultra settings maintain an average of 95.9 FPS. At 2560x1440, Ultra drops to 62.3 FPS, and at 3840x2160, it falls to 36.5 FPS, which is below the 60 FPS threshold for smooth gameplay.

Q: How does the i5-9400 compare to its closest rivals in synthetic benchmarks?

A: The i5-9400’s average benchmark score is 2,305, which is only 0.2% ahead of the Intel Core i3-10305 (2,300) and 0.2% ahead of the Intel Core i3-1125G4 (2,299). It is 0.4% ahead of the Intel Xeon E-2134 (2,295) and 0.6% behind the Intel Core i7-8809G (2,319).

Q: What is the GPU’s standing relative to other graphics cards?

A: The RTX 3080 sits in the 80th percentile of all GPUs with an average benchmark score of 35,787. Its nearest rival, the AMD Radeon Pro Duo, scores 35,860 (0.2% higher), while the AMD Radeon RX 7900 GRE scores 36,101 (0.9% higher). The RTX 3080 also edges out the RTX 5070 Ti Mobile by 1%.

Q: Does the combo rank differently in Rust compared to its component percentiles?

A: Yes. The combo ranks 652nd of 1,717 tested systems, which is higher than the CPU’s 50th percentile but lower than the GPU’s 80th percentile. This indicates Rust rewards the GPU more heavily, but the CPU prevents the system from reaching the top tier of results.

Q: What is the FPS penalty for using Ultra settings over Low at 1080p?

A: At 1920x1080, Ultra settings produce an average of 95.9 FPS, which is 46.9 FPS lower than the Low preset’s 142.8 FPS. That represents a 32.8% reduction in average frame rate when maxing out all visual options.

Q: Is the RTX 3080’s 10 GB VRAM sufficient for Rust at 4K?

A: The measured data shows playable results at 3840x2160 only on Low settings (88.7 FPS). High settings at 4K yield 52 FPS, while Ultra falls to 36.5 FPS. The 10 GB of GDDR6X memory with 760.3 GB/s bandwidth appears adequate for the Low preset, but higher presets likely stress memory capacity or bandwidth at 4K resolution.

GPU Role

The NVIDIA GeForce RTX 3080 is the dominant component in this pairing, and the Rust benchmark data strongly reflects that. The GPU’s 10 GB of GDDR6X memory on a 320-bit bus delivers 760.3 GB/s of bandwidth, which is critical for Rust’s large, streaming world. The benchmark results show that at 1080p, the GPU is not the limiting factor—even Ultra settings achieve 95.9 FPS, and Low settings reach 142.8 FPS. However, at 4K, the GPU’s workload increases dramatically, with High settings dropping to 52 FPS and Ultra to 36.5 FPS.

The RTX 3080’s boost clock of 1,710 MHz and 8,704 shading units provide raw compute power that Rust’s engine can utilize at higher resolutions. The data suggests a distinct GPU-bound region emerges at 2560x1440 and above, where the frame rate drops are proportionally larger than the resolution increase. For instance, moving from 1080p High (114.6 FPS) to 1440p High (83.1 FPS) is a 27.5% decrease, while moving from 1440p High to 4K High (52 FPS) is a 37.4% decrease. This nonlinear scaling points to the GPU’s memory bandwidth and fill rate being taxed at 4K, particularly with the 164.2 GPixel/s pixel rate and 465.1 GTexel/s texture rate.

The GPU’s 80th percentile ranking among all graphics cards is reflected in its ability to maintain playable frame rates at 1440p across all settings except Ultra. The RTX 3080’s 29.77 TFLOPS FP32 performance and 68 RT cores are likely underutilized in Rust, which is not a ray-tracing-heavy title, but the raw rasterization power still drives the high frame rates observed. The 4K Low result of 88.7 FPS is particularly telling: it suggests that when the rendering load is lightened, the GPU can still deliver near-90 FPS at 4K, meaning the hardware is capable but the higher presets impose a severe cost.

CPU Role

The Intel Core i5-9400 is a six-core, six-thread processor with a base clock of 2.90 GHz and a boost clock of 4.10 GHz. Its synthetic benchmark scores—8,030 in Cinebench R15 multi-core and 7,969 in Cinebench R23 multi-core—place it at the 50th percentile of all CPUs, with an average benchmark score of 2,305. In Rust, the CPU’s role becomes apparent when comparing the 1080p results across settings. At Low settings, the system achieves 142.8 FPS, but at Ultra, it drops to 95.9 FPS. This 46.9 FPS gap is larger than what would be expected from purely GPU-side changes, suggesting the CPU is not the primary bottleneck at 1080p.

The 4.10 GHz boost clock is modest by modern standards, and the 9 MB of shared L3 cache may limit how quickly the CPU can feed draw calls to the GPU. However, the data shows that at 1440p and 4K, the CPU’s influence wanes. For example, at 1440p Low, the system hits 128.1 FPS, which is only 14.7 FPS lower than 1080p Low (142.8 FPS). If the CPU were severely limiting, we would expect these two numbers to be nearly identical. Instead, the 10.3% decrease indicates the GPU is beginning to take on more of the load. At 4K Low, the frame rate drops to 88.7 FPS, a 30.8% decrease from 1440p Low, confirming that the RTX 3080 is the primary constraint at higher resolutions.

The i5-9400’s 50th percentile ranking is a double-edged sword. It is not a weak processor in absolute terms, but it lacks the multi-threading headroom of higher-tier CPUs. Rust is known to utilize multiple cores, and the six-thread configuration may be sufficient for 1080p High (114.6 FPS) but could struggle to push beyond that. The benchmark data does not show a scenario where the CPU is the sole bottleneck, as even at 1080p Low, the system exceeds 140 FPS, which is beyond what many displays can show. The 42.7 GB/s memory bandwidth and dual-channel DDR4 support are adequate for this workload, but the 65W TDP suggests a conservative power envelope that may limit sustained boost clocks.

Settings Recommendations

The measured FPS data provides a clear hierarchy for settings at each resolution. At 1920x1080, the Medium preset offers the best balance, delivering 125 FPS average, which is 10.4 FPS higher than High (114.6 FPS) and only 17.8 FPS lower than Low (142.8 FPS). Ultra at 1080p drops to 95.9 FPS, which is still playable but represents a 23.3% penalty over Medium. For players prioritizing smoothness over visual fidelity, Low at 1080p is the clear winner, but Medium provides a substantial visual upgrade with only a 12.5% performance loss.

At 2560x1440, the Medium preset again proves optimal, with an average of 99.6 FPS. This is 16.5 FPS higher than High (83.1 FPS) and 37.3 FPS higher than Ultra (62.3 FPS). Low at 1440p reaches 128.1 FPS, but the jump from Low to Medium costs 28.5 FPS, which is a significant trade-off. The data suggests that for a 1440p monitor with a 60Hz refresh rate, Medium is the highest preset that comfortably exceeds 60 FPS, while High is borderline and Ultra falls below the threshold.

At 3840x2160, only Low settings achieve a playable frame rate of 88.7 FPS. Medium drops to 58.7 FPS, which is below the 60 FPS target, and High falls to 52 FPS. Ultra at 4K is effectively unplayable at 36.5 FPS. The recommendation for 4K is straightforward: use Low settings if you want smooth gameplay, or accept that higher presets will require a lower resolution. Across all resolutions, the Medium preset provides the most consistent experience, never dropping below 58.7 FPS even at 4K, though that is marginal.

How This Combo Ranks

The combo rank of 652 out of 1,717 tested systems places this configuration in the 62nd percentile of all tested combos in Rust. This is a significant finding because it outperforms the CPU’s standalone 50th percentile ranking, indicating that the RTX 3080 boosts the system above what the processor alone would suggest. However, it falls short of the GPU’s 80th percentile, meaning the i5-9400 is holding back the RTX 3080 to some degree. The gap between the CPU’s percentile and the combo’s percentile suggests that Rust’s performance scaling is more sensitive to GPU capabilities than CPU strength, but the CPU still imposes a ceiling.

Looking at the nearest CPU rivals, the i5-9400’s performance is nearly identical to the Intel Core i3-10305 (0.2% delta) and the Intel Core i3-1125G4 (0.2% delta). This implies that upgrading from the i5-9400 to one of these chips would yield negligible gains in Rust. The GPU rivals tell a different story: the RTX 3080 is 0.9% behind the AMD Radeon RX 7900 GRE, which could translate to a few FPS in Rust. The combo’s 652nd rank out of 1,717 means there are 1,065 systems that perform better, but also 652 that perform worse, indicating this is a mid-to-upper-tier configuration for Rust specifically.

Measured FPS Breakdown

At 1920x1080, the average FPS values are: Low 142.8, Medium 125, High 114.6, and Ultra 95.9. The progression from Low to Ultra shows a total drop of 46.9 FPS. The step from Low to Medium costs 17.8 FPS, from Medium to High costs 10.4 FPS, and from High to Ultra costs 18.7 FPS. This non-linear pattern indicates that Ultra settings impose a disproportionately large performance penalty.

At 2560x1440, the values are: Low 128.1, Medium 99.6, High 83.1, and Ultra 62.3. The drop from Low to Medium is 28.5 FPS, which is larger than the equivalent 1080p drop. The Medium to High step costs 16.5 FPS, and High to Ultra costs 20.8 FPS. The 1440p results show a steeper descent, with Ultra falling 65.8 FPS below Low.

At 3840x2160, the values are: Low 88.7, Medium 58.7, High 52, and Ultra 36.5. The Low to Medium drop is 30 FPS, Medium to High is 6.7 FPS, and High to Ultra is 15.5 FPS. The 4K data reveals that the difference between Medium and High is much smaller than between other steps, suggesting a GPU resource threshold is crossed. The total spread at 4K is 52.2 FPS, the largest of any resolution.

Resolution Scaling

The FPS drop from 1080p to 4K reveals the system’s limiting component. At Low settings, 1080p yields 142.8 FPS, 1440p yields 128.1 FPS (a 10.3% drop), and 4K yields 88.7 FPS (a 30.8% drop from 1440p). These percentages indicate that the GPU is becoming the bottleneck at higher resolutions, as the CPU’s workload does not scale with pixel count. The 4K Low result of 88.7 FPS is still high, showing that the RTX 3080 has ample headroom when settings are minimal.

At Ultra settings, the scaling is more dramatic: 1080p produces 95.9 FPS, 1440p drops to 62.3 FPS (a 35% decrease), and 4K falls to 36.5 FPS (a 41.4% decrease from 1440p). The Ultra preset’s heavier shader and texture loads amplify the GPU’s workload, causing a steeper decline. This pattern suggests that at Ultra settings, the RTX 3080’s 10 GB VRAM and 760.3 GB/s bandwidth are being saturated, particularly at 4K where the 36.5 FPS result is a clear sign of memory pressure.

The data implies that for this combo, 1080p is the resolution where the CPU and GPU are best balanced. At 1080p Ultra, the 95.9 FPS result shows neither component is severely limiting. Moving to 1440p shifts the balance toward the GPU, and at 4K, the GPU is unequivocally the bottleneck. The i5-9400’s six cores appear sufficient to feed the RTX 3080 at 1080p and 1440p, but the GPU’s performance ceiling is reached at 4K. This is a classic pairing where the CPU is slightly underpowered for the GPU, but the GPU is powerful enough to dominate at higher resolutions.