Doom

The Intel Core i5-9400 paired with the NVIDIA GeForce RTX 3080 delivers a commanding performance profile in Doom, characterized by extreme frame rates at lower resolutions and a predictable transition to GPU-bound territory at 4K. The data indicates that this combination is exceptionally well-suited for high-refresh-rate 1080p and 1440p gaming, while still providing a smooth experience at 4K Ultra settings. This analysis breaks down the measured FPS across resolutions and settings, contextualizes the CPU's role, and offers practical guidance for optimizing the experience.

Resolution Scaling

The scaling from 1080p to 4K reveals a clear shift in system bottleneck. At 1920x1080 with High settings, the combo produces an average of 220.5 FPS. Moving to 2560x1440 drops that to 146.2 FPS, and at 3840x2160 it falls to 77.3 FPS. This represents a 65% reduction in frame rate from 1080p to 4K at High settings, which is a significant but expected drop given the 4x increase in pixel count.

The scaling pattern tells a story about the limiting component. At 1080p, the frame rates are so high (251.4 FPS on Low) that the Intel Core i5-9400's six cores and six threads are likely the primary constraint. The CPU's 2.90 GHz base and 4.10 GHz boost clocks are sufficient, but the architecture is working hard to feed the RTX 3080. As resolution increases, the load shifts to the GPU. The gap between Low and Ultra settings at 1080p is 67.7 FPS (251.4 vs 183.7), but at 4K, that same gap shrinks to 42.4 FPS (103.4 vs 61). This narrowing gap at higher resolutions is a classic sign of the GPU becoming the bottleneck.

For players targeting 4K, the scaling suggests that the RTX 3080's 10 GB of GDDR6X memory and 760.3 GB/s bandwidth are being utilized effectively. The GPU's 80th percentile ranking among all GPUs supports its capability here. Conversely, at 1080p, the CPU's 50th percentile ranking among all CPUs becomes more relevant. The data shows that this combination is balanced enough to avoid severe stutters, but the CPU will limit maximum FPS in the most demanding low-resolution scenarios. The 4K Low setting result of 103.4 FPS indicates that even when GPU load is reduced, the system maintains playable frame rates, confirming that the CPU is not a catastrophic bottleneck.

FAQ

Q: Is this combination capable of 4K gaming at high refresh rates?

A: At 3840x2160 with High settings, the average FPS is 77.3, and at Ultra it drops to 61. This is smooth for standard 60 Hz displays but not sufficient for 120 Hz or 144 Hz 4K monitors. The 4K Low setting achieves 103.4 FPS, which is playable but sacrifices visual quality.

Q: How does the CPU perform relative to its direct competitors?

A: The Intel Core i5-9400 has an average benchmark score of 2305, placing it in the 50th percentile. It is nearly identical to the Intel Core i3-10305 (2300, 0.2% faster) and the Intel Core i3-1125G4 (2299, 0.2% faster). It slightly trails the Intel Core i7-8809G (2319, -0.6% slower).

Q: What is the best settings preset for a balance of quality and performance?

A: For 1440p, High settings at 146.2 FPS provides a strong balance. At 4K, Medium settings at 94.5 FPS is the recommended starting point, as it offers a substantial improvement over Ultra (61 FPS) while maintaining visual fidelity close to High (77.3 FPS).

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

A: The data shows a good match overall. The combo ranks 600th out of 1681 tested combinations. The GPU is significantly more powerful than the CPU, but in Doom, the pairing yields high frame rates across all resolutions, with the CPU limiting only the absolute maximum FPS at 1080p.

Q: What frame rates can I expect at 1080p with Ultra settings?

A: The measured average FPS at 1920x1080 with Ultra settings is 183.7. This is well above the threshold for high-refresh-rate gaming and indicates the system is heavily GPU-bound at this resolution.

Q: How does the RTX 3080 compare to its nearest rivals?

A: The RTX 3080 has an average benchmark score of 35787, placing it in the 80th percentile. It is slightly behind the AMD Radeon RX 7900 GRE (36101, -0.9% slower) and AMD Radeon Pro Duo (35860, -0.2% slower), but ahead of the AMD Radeon 880M (35646, 0.4% faster) and the NVIDIA GeForce RTX 5070 Ti Mobile (35435, 1% faster).

Settings Recommendations

The measured data provides clear guidance for optimizing the experience across different display targets. For players with a 1080p monitor, the Ultra preset delivers 183.7 FPS, which is more than sufficient for any high-refresh-rate panel. Since the frame rate is already far above typical refresh rates, there is little reason to drop below Ultra, as the visual improvements are essentially free at this resolution. The Low preset at 251.4 FPS is only relevant for competitive play where every frame matters, but the 67.7 FPS difference between Low and Ultra is not worth the visual downgrade for most users.

At 2560x1440, the High preset at 146.2 FPS is the sweet spot. It provides a 26.1 FPS advantage over Ultra (120.1 FPS) while maintaining most of the visual quality. The Medium preset at 168.3 FPS is also viable for players who prioritize frame rate above all else, but High is the recommended balance. The Low preset at 193.1 FPS is unnecessary unless targeting a 240 Hz display.

For 4K gaming, the situation is more nuanced. The Ultra preset at 61 FPS is just on the edge of playability for a 60 Hz display, but the 16.3 FPS drop from High (77.3 FPS) is significant. The Medium preset at 94.5 FPS is the recommended choice for 4K, as it offers a 33.5 FPS improvement over Ultra while remaining visually close to the High preset. The Low preset at 103.4 FPS provides minimal additional performance over Medium and should be avoided due to the substantial visual compromise. The data suggests that Medium or High at 4K is the optimal configuration, depending on whether the player prioritizes visual fidelity or headroom for frame drops.

How This Combo Ranks

In the grand scheme of tested hardware combinations, this pairing of the Intel Core i5-9400 and NVIDIA GeForce RTX 3080 ranks 600th out of 1681 combos in Doom. This places it in the top 36% of all tested systems, which is a solid result given the CPU's mid-range positioning. The rank reflects the fact that the RTX 3080 is doing the heavy lifting, as the GPU's 80th percentile ranking is significantly higher than the CPU's 50th percentile ranking.

The ranking indicates that this combo outperforms a majority of systems, but it is not at the absolute top tier. Systems with newer, higher-core-count CPUs would likely rank higher, as they would be able to sustain higher frame rates at 1080p. However, the practical impact of the CPU's limitations is minimal at 1440p and above, where the GPU is the primary bottleneck. For a 1440p or 4K gaming rig, this rank is respectable and confirms that the combination is well-balanced for those resolutions.

The deltaPct values for the GPU's rivals show that the RTX 3080 is closely matched with several other high-end cards. The performance difference between the RTX 3080 and the AMD Radeon RX 7900 GRE is only 0.9%, which is within the margin of error for many benchmarks. This suggests that the combo's rank is more dependent on the CPU than on minor GPU differences. The CPU's nearest rivals are also within a 1% performance band, indicating that the i5-9400 is a stable, predictable performer that does not introduce significant variability into the system's overall ranking.

CPU Role

The Intel Core i5-9400 is a six-core, six-thread processor based on the Coffee Lake architecture. It operates at a base clock of 2.90 GHz and boosts up to 4.10 GHz, with a 65 W TDP. The CPU has 9 MB of shared L3 cache and supports dual-channel DDR4 memory with a bandwidth of 42.7 GB/s. These specifications place it firmly in the mid-range segment, and its benchmark scores reflect this positioning.

In Doom, the CPU's role is to feed the GPU with draw calls and game logic. The six cores and six threads are sufficient for this game, as evidenced by the high frame rates at lower resolutions. The 4.10 GHz boost clock is crucial for single-threaded performance, which Doom relies on heavily. The CPU's average benchmark score of 2305 places it in the 50th percentile, meaning it performs better than half of all CPUs tested. Its nearest rivals, the Intel Core i3-10305 and Intel Core i3-1125G4, have nearly identical scores (2300 and 2299, respectively), confirming that the i5-9400 is a dependable, if unremarkable, performer.

The data shows that the CPU does not become a severe bottleneck at 4K. The 4K Low setting still achieves 103.4 FPS, which indicates that the CPU can keep up with the GPU's output even when the GPU is less stressed. However, at 1080p Low settings, the 251.4 FPS result suggests that the CPU is reaching its limits, as the GPU could likely produce more frames if it were paired with a faster processor. For this game, the i5-9400 is a capable partner for the RTX 3080, providing enough performance to avoid stutters and maintain high average frame rates across all tested configurations.

Measured FPS Breakdown

The measured FPS data provides a complete picture of the system's performance across three resolutions and four settings presets.

At 1920x1080, the average FPS ranges from 251.4 on Low to 183.7 on Ultra. The Medium preset achieves 241.9 FPS, and High delivers 220.5 FPS. The step-down from Low to Medium is only 9.5 FPS, while the drop from High to Ultra is 36.8 FPS. This indicates that the Ultra preset imposes a significant performance cost relative to High, making High the most efficient choice at this resolution.

At 2560x1440, the average FPS ranges from 193.1 on Low to 120.1 on Ultra. Medium achieves 168.3 FPS, and High delivers 146.2 FPS. The scaling is more gradual here, with a 47.2 FPS difference between Low and Medium, a 22.1 FPS difference between Medium and High, and a 26.1 FPS difference between High and Ultra. This pattern suggests that the GPU is becoming the limiting factor, as the performance cost of each settings tier is more consistent.

At 3840x2160, the average FPS ranges from 103.4 on Low to 61 on Ultra. Medium achieves 94.5 FPS, and High delivers 77.3 FPS. The differences between settings are 8.9 FPS (Low to Medium), 17.2 FPS (Medium to High), and 16.3 FPS (High to Ultra). The system is clearly GPU-bound at this resolution, as the total range from Low to Ultra is only 42.4 FPS, compared to 67.7 FPS at 1080p. The 4K Ultra result of 61 FPS is the only configuration that dips below the 60 FPS threshold, making it the least desirable preset for smooth gameplay.