Doom

# How This Combo Ranks

The Intel Core i5-9400 paired with the NVIDIA GeForce RTX 5090 places at rank 277 out of 1,681 tested combos in Doom. This positions the configuration in the upper tier of all tested systems, outperforming roughly 83.5% of combinations in the database. The ranking reflects a substantial performance ceiling, though it is not at the very top of the leaderboard—a gap that becomes more understandable when examining the CPU's role in this specific title.

The combo's percentile placement is influenced heavily by the GPU's raw capability. The RTX 5090 sits at the 94th percentile among all GPUs, with an average benchmark score of 84,306 across all tested workloads. Its nearest rivals in the GPU benchmark pool include the RTX 5090 D (0.1% slower), RTX 5050 Mobile (0.2% slower), AMD Radeon PRO W6600 (1.3% slower), and NVIDIA CMP 40HX (1.6% faster). These small deltaPct values indicate that the RTX 5090 is operating in a very tight performance cluster at the top of the GPU hierarchy.

On the CPU side, the i5-9400 sits at the 50th percentile among all processors, with a modest average benchmark score of 2,305. Its nearest rivals—the Core i3-10305, Core i3-1125G4, Xeon E-2134, and Core i7-8809G—are all within 0.6% of its average score, indicating that this six-core processor is firmly in the mid-range of the CPU landscape. The combination of a top-tier GPU with a mid-range CPU creates a notable asymmetry that manifests in the measured frame rates across resolutions and settings.

# GPU Role

The RTX 5090 brings substantial specifications to this pairing. It features 32 GB of GDDR7 memory on a 512-bit bus, delivering 1.79 TB/s of bandwidth. The memory operates at 1750 MHz (28 Gbps effective), which provides ample headroom for Doom's texture-heavy environments at any resolution. The GPU's 21,760 shading units, 680 texture mapping units, and 176 raster output pipelines work in concert to push high pixel and texture rates: 423.6 GPixel/s and 1,636.8 GTexel/s respectively.

The card's compute capabilities are equally formidable. It delivers 104.8 TFLOPS of FP32 performance, with FP16 also at 104.8 TFLOPS (1:1 ratio). The 170 ray tracing cores and 680 tensor cores provide additional specialized processing power, though Doom's 2016 engine relies more on traditional rasterization than ray tracing. The GPU's boost clock of 2407 MHz (base 2017 MHz) contributes to its ability to maintain high frame rates even under sustained load.

In Doom specifically, the GPU's dominance is evident in the measured results. At 1080p Low settings, the combo achieves 257.2 FPS average—a figure that approaches the practical limits of many display refresh rates. The gap between Low and Ultra settings at 1080p is 42.1 FPS (257.2 vs 215.1), showing that even at maximum settings, the GPU provides more than sufficient throughput. The RTX 5090's 94th percentile ranking among all GPUs is reflected in these numbers, as the card consistently delivers frame rates that would typically be associated with much lower graphical loads.

# Resolution Scaling

The measured data reveals a predictable scaling pattern as resolution increases from 1080p to 4K. At High settings, the average FPS drops from 227.9 at 1920x1080 to 196.1 at 2560x1440, then to 122.1 at 3840x2160. This represents a 46.4% reduction from 1080p to 4K at High settings. The scaling is steeper at Low settings: 257.2 FPS at 1080p falls to 222 at 1440p and 158.4 at 4K—a 38.4% drop from 1080p to 4K.

The pattern across settings tells a consistent story about the limiting component. At 1080p, the delta between Low and Ultra is 42.1 FPS (257.2 to 215.1), while at 4K, the same comparison shows a 61.7 FPS difference (158.4 to 96.7). The widening gap at higher resolutions indicates that the GPU becomes increasingly stressed as pixel count rises, but the CPU's influence is also visible. At 1080p Low, the 257.2 FPS ceiling suggests the i5-9400's six cores and six threads may be approaching their limit in feeding the RTX 5090—further evidence that this processor, with its 2.90 GHz base and 4.10 GHz boost clocks, cannot fully unlock the GPU's potential at lower resolutions.

The 4K Ultra result of 96.7 FPS is particularly informative. It shows that even with a CPU sitting at the 50th percentile, the RTX 5090 can maintain nearly 100 FPS at maximum settings in 4K. The 4K Low result of 158.4 FPS reinforces that the GPU remains the dominant factor at this resolution, as the CPU bottleneck is less pronounced when the GPU is working harder.

# Settings Recommendations

Examining the measured rows, the optimal balance between visual fidelity and frame rate appears at the High preset. At 1080p High, the combo delivers 227.9 FPS; at 1440p High, 196.1 FPS; and at 4K High, 122.1 FPS. These numbers represent a comfortable margin above the 60 FPS threshold for smooth gameplay, while providing significantly better visual quality than Low or Medium presets.

The Ultra preset, while offering the maximum visual quality, shows diminishing returns. At 4K Ultra, the average FPS drops to 96.7—still playable, but 25.4 FPS below the High preset's 4K result. The Medium preset at 4K (141.8 FPS) and Low preset at 4K (158.4 FPS) both surpass High, but at the cost of reduced visual fidelity. For most users, High at 1440p provides the best experience: 196.1 FPS with substantial graphical detail, representing a 17.6 FPS improvement over Ultra at the same resolution (178.6 FPS).

The data suggests that High settings at 1440p or 4K offer the most compelling combination of performance and image quality. At 4K, the 122.1 FPS average at High is nearly double the 60 FPS standard, providing headroom for demanding scenes. Users with 1440p displays can push to Ultra and still maintain 178.6 FPS, though the 17.5 FPS gain from High to Ultra may not justify the visual difference for competitive play.

# FAQ

Q: How does this combo perform at 4K Ultra settings?

A: The measured average FPS at 3840x2160 with Ultra settings is 96.7 FPS. This is the lowest result among all tested resolution and settings combinations, but it remains above 60 FPS, indicating smooth gameplay even at maximum graphical load.

Q: Is the CPU or GPU the limiting factor in Doom?

A: The data indicates the GPU is the primary bottleneck at higher resolutions, as evidenced by the 61.7 FPS difference between Low and Ultra at 4K. However, at 1080p Low (257.2 FPS), the CPU's mid-range position (50th percentile) suggests it may constrain the RTX 5090's full potential at lower resolutions.

Q: What is the best resolution for this combo?

A: Based on the measured frames, 2560x1440 at High settings (196.1 FPS) offers the best balance of performance and visual quality. At 4K High, the combo still delivers 122.1 FPS, making 4K viable, but 1440p provides a larger margin above 60 FPS.

Q: How does the RTX 5090 compare to its closest rivals?

A: The RTX 5090's average benchmark score of 84,306 is within 1.6% of its nearest competitors. It trails the NVIDIA CMP 40HX by 1.6%, while leading the RTX 5090 D by 0.1%, RTX 5050 Mobile by 0.2%, and AMD Radeon PRO W6600 by 1.3%.

Q: How does the i5-9400's benchmark score compare to similar processors?

A: The i5-9400's average score of 2,305 is 0.2% ahead of the Core i3-10305 (2,300) and Core i3-1125G4 (2,299), 0.4% ahead of the Xeon E-2134 (2,295), and 0.6% behind the Core i7-8809G (2,319). These differences are negligible in real-world terms.

Q: Does the combo maintain playable frame rates at all tested settings?

A: Yes. The lowest measured average FPS is 96.7 at 4K Ultra, which remains well above the 60 FPS standard. The highest is 257.2 FPS at 1080p Low, demonstrating that the combo never drops below playable thresholds in any tested configuration.

# CPU Role

The Intel Core i5-9400 is a six-core, six-thread processor from the Coffee Lake architecture, manufactured on Intel's 14 nm process node. It operates at a 2.90 GHz base clock with a 4.10 GHz boost clock, drawing 65 W TDP. The processor includes 64 KB L1 cache per core, 256 KB L2 per core, and 9 MB shared L3 cache. Memory support is DDR4 on a dual-channel interface, providing 42.7 GB/s of bandwidth. The CPU connects via PCIe Gen 3 with 16 lanes.

In Doom, the CPU's impact is most visible at lower resolutions and settings where the GPU is not fully taxed. At 1080p Low, the 257.2 FPS result represents the highest frame rate in the measured set, yet this figure likely approaches the i5-9400's practical ceiling in this title. The processor's 50th percentile ranking among all CPUs, with an average benchmark score of 2,305, places it in the middle of the performance distribution. Its Cinebench scores—803 in R15 multi-core, 113 in R15 single-core, 3,346 in R20 multi-core, 472 in R20 single-core, 7,969 in R23 multi-core, and 1,125 in R23 single-core—confirm this mid-range positioning.

The CPU's six threads may be a limiting factor in Doom's more demanding scenarios, as modern titles often benefit from additional thread counts. However, the measured results show that the i5-9400 still enables high frame rates across all settings. At 1440p High, the combo achieves 196.1 FPS; at 4K High, 122.1 FPS. These figures indicate that while the CPU may not fully saturate the RTX 5090 at lower resolutions, it does not prevent the system from delivering excellent performance in Doom. The 42.1 FPS gap between Low and Ultra at 1080p (257.2 vs 215.1) suggests some CPU-bound behavior, but the 61.7 FPS gap at 4K (158.4 vs 96.7) clearly shows the GPU taking over as the dominant constraint.