Doom

The Intel Core i5-9400 and NVIDIA GeForce GTX 1080 Ti pairing delivers a fascinating split personality in Doom. At 1080p, the combo is a high-refresh monster, but at 4K Ultra, it stumbles below the 60 FPS line. This data reveals a classic case of a legacy GPU holding back a capable, mid-range CPU, and the resolution scaling quantifies exactly where that bottleneck shifts.

Resolution Scaling — how FPS drops from 1080p to 4K and what it says about the limiting component

The measured frames per second reveal a dramatic and highly informative scaling curve. Moving from 1920x1080 to 2560x1440 at High settings, the average FPS drops from 156.3 to 103.2, a decline of roughly 34%. The subsequent jump to 3840x2160 sees a further drop to 54.7 FPS, representing another 47% reduction from the 1440p figure. This trajectory shows that the performance penalty for resolution increases disproportionately as pixel count rises.

At the Low preset, the trend is even more pronounced. The combo achieves 215.3 FPS at 1080p, which falls to 140.5 FPS at 1440p, and then plummets to 76.7 FPS at 4K. The 4K Low result is actually higher than the 4K High result, which confirms that the GPU is the primary constraint at this resolution. The sheer pixel throughput required at 3840x2160 overwhelms the GTX 1080 Ti, regardless of the graphical fidelity settings.

The scaling from Low to Ultra at each resolution tells a similar story. At 1080p, the gap between Low (215.3 FPS) and Ultra (132.2 FPS) is significant, but both are highly playable. At 4K, the gap narrows in absolute terms: Low (76.7 FPS) versus Ultra (46.5 FPS). This compression of the performance envelope at 4K is the signature of a GPU-bound scenario. The CPU has enough headroom to feed the GPU at lower resolutions, but the GPU’s compute and memory bandwidth limits become the wall at higher pixel counts.

CPU Role — cores, clocks, and how they relate to this game's results

The Intel Core i5-9400 is a 6-core, 6-thread processor based on the Coffee Lake architecture, with a base clock of 2.90 GHz and a boost clock of 4.10 GHz. In Doom, this configuration appears sufficient to avoid becoming a bottleneck at most settings. The evidence is in the 1080p numbers: at Low settings, the system produces 215.3 FPS, a figure that far exceeds what most displays can show. This high frame rate indicates that the CPU is feeding the GPU efficiently without becoming a limiting factor.

The processor’s benchmark scores provide context for its gaming capabilities. Its Cinebench R23 multi-core score is 7969, and its single-core score is 1125. These scores place the i5-9400 in the 50th percentile of all CPUs, with an average benchmark score of 2305. Its nearest rivals in synthetic benchmarks are the Intel Core i3-10305 and Intel Core i3-1125G4, both with average scores around 2300 and a deltaPct of 0.2. This suggests the i5-9400 is a solid, mid-pack performer, but not a top-tier chip.

The data indicates that the CPU’s role in Doom is to provide a stable foundation. The 6 cores and 6 threads, combined with the 9 MB of shared L3 cache, are enough to maintain high frame rates. The lack of hyper-threading does not appear to hurt in this specific title, as the frame rates remain consistently high at 1080p. The bottleneck only becomes apparent when the GPU is stressed at higher resolutions, which reflects the i5-9400’s adequacy for this game.

How This Combo Ranks — use comboRankInGame vs other tested combos

Within the database of tested hardware combinations, this specific pairing of the i5-9400 and GTX 1080 Ti holds a rank of 1003 out of 1681 combos for Doom. This places it in the upper-middle tier of all tested systems. While it is not a top-100 performer, it sits ahead of a substantial portion of the field, which aligns with the high frame rates measured at 1080p and 1440p.

The rank suggests that while the individual components are not the absolute fastest, their combination yields a balanced experience for this game. The GTX 1080 Ti’s age is a factor; it was released in 2017, and its successor, the GeForce 20 series, has since arrived. However, the data shows that it still competes well. The GPU’s average benchmark score is 19402, which puts it in the 61st percentile of all GPUs. Its nearest rival in synthetic tests is the NVIDIA GeForce GTX 780, with an almost identical average score of 19405 and a deltaPct of 0.

The combo’s ranking relative to its position in the overall pool of hardware is more impressive than the raw rank suggests. A rank of 1003 out of 1681 means it outperforms roughly 40% of all tested configurations. This is notable because the CPU is a mainstream part, not a high-end enthusiast chip. The pairing works well because the GPU provides the muscle, and the CPU provides just enough support to avoid dragging down performance.

Measured FPS Breakdown — resolution by resolution, settings by settings, exact numbers

The dataset provides a complete matrix of average FPS across three resolutions and four quality presets. At 1920x1080, the results are: Low 215.3 FPS, Medium 189 FPS, High 156.3 FPS, and Ultra 132.2 FPS. These figures demonstrate a smooth scaling curve, with each step up in quality costing a consistent amount of performance. The delta between Low and Ultra is 83.1 FPS, indicating a significant impact from visual fidelity settings.

At 2560x1440, the performance remains strong but shows the expected decline: Low 140.5 FPS, Medium 121.2 FPS, High 103.2 FPS, and Ultra 86.1 FPS. The drop from 1080p to 1440p at Ultra is from 132.2 to 86.1 FPS, a reduction of 46.1 FPS. This is a substantial hit, but the resulting frame rates are still well above the threshold for smooth gameplay on most monitors.

At 3840x2160, the results highlight the GPU’s limitations: Low 76.7 FPS, Medium 64.9 FPS, High 54.7 FPS, and Ultra 46.5 FPS. The Ultra preset at 4K is the only configuration that dips below 60 FPS, which is a critical threshold for many players. The data shows that the GTX 1080 Ti, while powerful, cannot maintain high refresh rates at 4K with maximum settings in Doom. The difference between 4K Low and 4K Ultra is 30.2 FPS, showing that even at this resolution, settings still matter, but the ceiling is capped by the GPU’s raw power.

GPU Role — VRAM, clocks, and how they relate to this game's results

The NVIDIA GeForce GTX 1080 Ti is a Pascal-architecture GPU built on a 16 nm process. It features 11 GB of GDDR5X memory on a 352-bit bus, yielding a bandwidth of 484.4 GB/s. This memory configuration is crucial for Doom at higher resolutions, as the game’s textures and geometry demand significant memory throughput. The 11 GB capacity is more than sufficient for this title, even at 4K Ultra, preventing any potential stuttering from VRAM exhaustion.

The GPU’s clocks are set at a base of 1481 MHz and a boost of 1582 MHz. The memory operates at 1376 MHz, which translates to 11 Gbps effective. These clock speeds, combined with 3584 shading units and 224 texture mapping units, deliver a raw compute performance of 11.34 TFLOPS. This is the engine that drives the high frame rates at 1080p and 1440p. The pixel rate of 139.2 GPixel/s and texture rate of 354.4 GTexel/s are the specs that determine how quickly the GPU can fill the screen.

The benchmark data shows that the GTX 1080 Ti’s performance is consistent with its hardware specifications. Its Passmark G3D score of 18600 and Geekbench Vulkan score of 83108 confirm its capability. However, its age is evident in its nearest rivals; the NVIDIA TITAN Xp is only 1.1% faster in average score, while the AMD Radeon Pro 560X is 0.1% slower. The data suggests that the GPU is the limiting factor at 4K Ultra, where the 46.5 FPS result falls short of the 60 FPS target.

FAQ

*Q: Can this combo run Doom at 4K with High settings?*

A: Yes, but just barely. The measured average FPS at 3840x2160 with High settings is 54.7 FPS. This is below the 60 FPS standard for smooth play, but it is still playable for many users.

Q: What is the best resolution for this combo to achieve 144 FPS?

A: The data shows that at 1920x1080 with Medium settings, the combo achieves 189 FPS, and at High settings, it reaches 156.3 FPS. Both are above 144 FPS, making 1080p the ideal resolution for high-refresh-rate monitors.

Q: Is the CPU or GPU the bottleneck at 1080p?

A: The data suggests the GPU is still the primary constraint, but the CPU is not a limiting factor. At 1080p Low, the system produces 215.3 FPS, which indicates the CPU can feed the GPU efficiently. The Intel Core i5-9400’s 6 cores and 6 threads are sufficient for this game.

Q: How much performance is lost when moving from 1080p to 4K at Ultra settings?

A: The average FPS drops from 132.2 at 1920x1080 to 46.5 at 3840x2160, a reduction of 85.7 FPS. This represents a performance loss of over 60%.

Q: Does the GTX 1080 Ti have enough VRAM for this game?

A: Yes. The 11 GB of GDDR5X memory is more than adequate for Doom. The GPU’s memory bandwidth of 484.4 GB/s ensures that the game’s assets are loaded quickly, and the capacity prevents any issues at 4K.

*Q: How does this combo rank among all tested systems for Doom?*

A: This pairing holds a rank of 1003 out of 1681 tested combos. This places it in the upper-middle tier, outperforming roughly 40% of all tested configurations.

Settings Recommendations

For players targeting 60 FPS, the data clearly points to 2560x1440 with Ultra settings as the best option. The measured average FPS is 86.1, which provides a comfortable margin above the 60 FPS target. This configuration offers the highest visual fidelity while maintaining excellent smoothness. The 4K resolution is only viable with Low settings, where the combo hits 76.7 FPS, or Medium settings at 64.9 FPS. High and Ultra at 4K dip below 60 FPS and are not recommended for a consistent experience.

For those with high-refresh-rate monitors, 1920x1080 is the sweet spot. The High preset at 156.3 FPS is an excellent balance of visual quality and speed, easily driving a 144 Hz display. The Medium preset at 189 FPS is even faster, but the visual trade-off may not be worth it for most players. The Ultra preset at 132.2 FPS is also viable for 120 Hz panels, offering the best image quality without sacrificing too much frame rate.

The data suggests that the i5-9400 and GTX 1080 Ti combination is best utilized at 1440p. The 2560x1440 resolution with High settings (103.2 FPS) provides a fantastic balance, offering a significant visual upgrade over 1080p while maintaining frame rates well above 60 FPS. The GPU’s 11 GB of VRAM and 484.4 GB/s bandwidth are well-suited to this resolution, making it the recommended target for a premium experience. Ultimately, the choice depends on the display’s refresh rate and the user’s preference for visual fidelity over raw speed.