Doom

The AMD Ryzen 5 8400F pairs a 6-core, 12-thread Zen 4 design with a 4.20 GHz base and 4.70 GHz boost clock. Its 16 MB of shared L3 cache and dual-channel DDR5 memory support provide a solid foundation for gaming workloads. In synthetic benchmarks, the processor’s 82nd percentile ranking among all CPUs is backed by a Cinebench R23 multi-core score of 20851 and a single-core score of 2943. The 8400F sits in a tight competitive cluster; its nearest rivals include the AMD Ryzen 7 2700X, which it matches at a 0% delta, and the AMD Ryzen 5 7500F, which it leads by 0.3%. This indicates that the CPU’s performance headroom is more than sufficient for the frame rates observed in Doom at all tested settings.

The processor’s 12 threads are well-utilized by the game’s engine, which scales effectively across multiple cores. At 1080p with Low settings, the combo achieves 383.4 FPS, a figure that is not constrained by the CPU’s architectural limits. The fact that the same CPU can push frame rates from 270.5 FPS at Ultra to 383.4 FPS at Low at 1080p demonstrates that the 8400F is not a bottleneck in this title; the variation is entirely attributable to GPU load. Even at 4K, where the GPU becomes the primary driver, the CPU maintains enough throughput to feed the RTX 4090 without introducing stutter. The processor’s 65W TDP and active production status make it a modern, efficient choice for this combination.

GPU Role

The NVIDIA GeForce RTX 4090 is the dominant component in this pairing, featuring 24 GB of GDDR6X memory on a 384-bit bus with 1.01 TB/s of bandwidth. Its Ada Lovelace architecture, built on a 5 nm process, includes 16384 shading units and 128 RT cores. The GPU’s 91st percentile ranking among all graphics cards is reflected in its Passmark G3D score of 38194, though its nearest rivals in aggregate benchmarks—such as the NVIDIA Tesla T4 and AMD Radeon Pro Vega 56—are data-center or workstation parts that do not directly compete in gaming scenarios.

The RTX 4090’s clock behavior is critical to understanding the measured results. With a base clock of 2235 MHz and a boost clock of 2520 MHz, the card scales its frequency based on thermal and power headroom. In Doom, the GPU’s immense rendering capabilities are evident in the scaling pattern: at 1080p Low, the 383.4 FPS average is likely limited by the game’s engine or CPU draw-call overhead rather than the GPU itself. The 24 GB VRAM buffer is never a constraint at any resolution tested, as the game’s texture requirements are far below this capacity. The card’s 1.01 TB/s memory bandwidth ensures that even at 4K Ultra, where fill-rate demands spike, the GPU can sustain 95.3 FPS without memory-related dips.

The RTX 4090’s role shifts from being over-provisioned at 1080p to being the definitive limiting factor at 4K. The delta between settings at each resolution confirms this: at 4K, the spread from Low (154.6 FPS) to Ultra (95.3 FPS) is 59.3 FPS, whereas at 1080p the same spread is only 112.9 FPS. This indicates that as resolution increases, the GPU’s compute and memory subsystems become saturated, while the CPU’s contribution remains constant. The card’s end-of-life production status and 450W TDP are worth noting, but in this title, the RTX 4090 delivers frame rates that exceed the refresh rate of most monitors at 1440p and remain highly playable at 4K.

Settings Recommendations

The measured FPS rows provide a clear hierarchy for optimal experience. At 4K, the High preset delivers 116.5 FPS, which is superior to Ultra’s 95.3 FPS while offering a 21.2 FPS improvement. The Medium preset at 4K produces 137.4 FPS, but the visual fidelity loss from High is not justified by the additional 20.9 FPS. For 4K users, High is the sweet spot: it maintains a fluid frame rate above 100 FPS while preserving most graphical features. Ultra at 4K is only viable for players who prioritize image quality over frame rate, as the 95.3 FPS result is still above 60 FPS but leaves little headroom for demanding scenes.

At 1440p, the recommendation shifts toward Ultra. The Ultra preset yields 170.4 FPS, which is well above the 144 Hz refresh rate common at this resolution. The jump from High (210.7 FPS) to Ultra (170.4 FPS) represents a 40.3 FPS cost, but the visual improvements are worth it for most users. The Medium preset at 248.6 FPS and Low at 289.8 FPS are excessive for typical 1440p displays, making Ultra the best balance of quality and performance. For 1080p, the data suggests using Ultra as the default. The 270.5 FPS average at Ultra is far beyond any 1080p monitor’s refresh rate, and the downgrade to Medium (366.6 FPS) or Low (383.4 FPS) provides no practical benefit for the visual compromise.

The overall recommendation across all resolutions is to prioritize High at 4K and Ultra at 1440p and 1080p. The measured data shows diminishing returns on lower settings, as the RTX 4090 is powerful enough to render Doom at maximum quality without dropping below 95 FPS at any resolution tested.

How This Combo Ranks

This specific combination of the AMD Ryzen 5 8400F and NVIDIA GeForce RTX 4090 ranks 40th out of 1681 tested combos in Doom. This places the pairing in the top 2.4% of all configurations, which is a strong result given that the CPU is a mid-range part while the GPU is a flagship. The ranking reflects the game’s heavy reliance on GPU performance; the RTX 4090’s dominance compensates for the 8400F’s modest position in the CPU hierarchy. The CPU’s 82nd percentile and the GPU’s 91st percentile combine to produce a system that outperforms most high-end builds with slower graphics cards.

The rank of 40 is particularly notable because it sits above configurations that might feature more expensive CPUs. This is due to Doom’s engine, which is optimized for high frame rates and does not demand excessive CPU resources. The 8400F’s 6-core, 12-thread layout is sufficient to avoid becoming a bottleneck, allowing the RTX 4090 to operate at full capacity. The delta between this combo and the top-ranked systems is likely minimal, as the game’s frame rates are already near the engine’s ceiling at 1080p. The data suggests that upgrading the CPU to a higher-tier model would yield negligible gains in this specific title, as the measured FPS at 1080p Low (383.4) approaches the practical limit for the game’s rendering loop.

Resolution Scaling

The FPS drop from 1080p to 4K reveals the limiting component in this system. At Ultra settings, the average FPS falls from 270.5 at 1080p to 170.4 at 1440p, a 37.0% reduction, and then to 95.3 at 4K, a further 44.1% reduction from 1440p. This scaling pattern is characteristic of a GPU-bound scenario. The RTX 4090’s rendering workload quadruples in pixel count from 1080p to 4K, and the frame rate drops accordingly. The CPU’s contribution remains constant across resolutions, as evidenced by the fact that the 8400F can maintain over 380 FPS at 1080p Low without issue.

The data shows that the system is GPU-limited at all resolutions above 1080p. At 1080p, the CPU may still have some headroom, as the frame rate at Low (383.4) is only 13.9% higher than at Medium (366.6), suggesting that the GPU is nearing its engine-level peak. The transition from 1440p to 4K is the most punishing, with a 44.1% FPS loss at Ultra. This confirms that the RTX 4090’s 24 GB VRAM and 1.01 TB/s bandwidth are being fully exercised at 4K, and that the bottleneck is the GPU’s compute throughput rather than memory capacity. For users targeting 4K, the recommendation to use High settings is supported by the scaling data, as it reduces the pixel-shading load enough to maintain a 116.5 FPS average.

Measured FPS Breakdown

At 1920x1080, the combo delivers its highest frame rates across all settings. The Low preset averages 383.4 FPS, followed by Medium at 366.6 FPS, High at 329.4 FPS, and Ultra at 270.5 FPS. The spread from Low to Ultra is 112.9 FPS, indicating that the game’s settings have a significant impact on GPU load even at this resolution. The 1080p results are all above 270 FPS, making this resolution ideal for competitive play or high-refresh-rate monitors.

At 2560x1440, the average FPS drops noticeably but remains exceptionally high. Low settings produce 289.8 FPS, Medium 248.6 FPS, High 210.7 FPS, and Ultra 170.4 FPS. The delta between Low and Ultra is 119.4 FPS, similar to 1080p, which shows that the GPU’s relative performance scaling is consistent. The 1440p results are all above 170 FPS, which exceeds the refresh rate of most gaming monitors. At 3840x2160, the frame rates become more moderate. Low averages 154.6 FPS, Medium 137.4 FPS, High 116.5 FPS, and Ultra 95.3 FPS. The drop from Low to Ultra is 59.3 FPS, a smaller absolute difference than at lower resolutions, but the percentage loss is similar. The 4K results show that the RTX 4090 is still capable of exceeding 60 FPS at maximum settings, but the gap between High and Ultra (21.2 FPS) is a meaningful trade-off for visual quality.

Across all resolutions, the Low preset consistently delivers the highest frame rates, but the marginal gains over Medium are small at 1080p (16.8 FPS) and 1440p (41.2 FPS). The data indicates that the RTX 4090 is powerful enough to run Doom at High or Ultra settings at any resolution without dropping below 95 FPS, making the lower presets unnecessary for most users.