Doom

The pairing of the Intel Core i5-12400 with the NVIDIA GeForce RTX 4090 in Doom produces a fascinating study in bottleneck dynamics, where the GPU's raw power is frequently restrained by the CPU's mid-range positioning. The data indicates that this combo ranks 158th out of 3712 tested configurations, placing it in the top 4.3% of all tested systems, a strong result that nonetheless shows clear limitations at lower resolutions. This analysis examines how the frame rates scale across resolutions and settings, and what that reveals about the balance between these two components.

Resolution Scaling

The measured FPS data reveals a clear pattern of diminishing returns as resolution increases, which is classic behavior for a system where the CPU becomes the primary limiting factor at lower resolutions. At 1080p, the difference between Low and Ultra settings is a relatively narrow 96 FPS (363 down to 267), indicating that the CPU is struggling to feed frames to the GPU quickly enough, even with the most demanding settings. The i5-12400's 6 cores and 12 threads, with a boost clock of 4.40 GHz, simply cannot generate frames fast enough to fully saturate the RTX 4090's capabilities at this resolution.

Moving to 1440p, the frame rates become more reasonable, with Low settings producing 287 FPS and Ultra producing 173 FPS. This represents a more balanced workload, as the GPU begins to take on more of the rendering burden, but the CPU is still a significant factor. The gap between Low and Ultra narrows to 114 FPS, which is proportionally similar to the 1080p results, suggesting that the CPU is still the main constraint. The RTX 4090, with its 16,384 shading units and 82.58 TFLOPS of FP32 performance, is capable of far more at this resolution, but the CPU prevents it from reaching its full potential.

At 4K (3840x2160), the scales tip decisively in favor of the GPU being the limiting component. The frame rates drop to a range of 94 FPS at Ultra to 156 FPS at Low, and the difference between settings becomes more pronounced in absolute terms. This is where the RTX 4090's 24 GB of GDDR6X memory and 1.01 TB/s of bandwidth start to matter, as the higher pixel count demands more from the GPU's texture and memory subsystems. The fact that the 4K Ultra score is only 94 FPS, while 1080p Ultra is 267 FPS, shows that the GPU is now the bottleneck, and the CPU has more headroom to work with.

The data across all three resolutions suggests that this combo is best suited for high-refresh-rate 1440p gaming, where the CPU can keep up with the GPU’s output, or for 4K gaming where the GPU is fully utilized. At 1080p, the system is clearly CPU-limited, meaning that a faster processor would yield higher frame rates, but the RTX 4090 is being underutilized. The 115 FPS minimum at 4K Medium and 294 FPS minimum at 1080p Medium show that frame pacing is generally stable, but the CPU's limitations are evident in the lower minimums at 1080p.

CPU Role

The Intel Core i5-12400 is a 6-core, 12-thread processor based on the Alder Lake architecture, with a base clock of 2.50 GHz and a boost clock of 4.40 GHz. Its benchmark scores, such as a Cinebench R23 multicore score of 15989 and a single-core score of 2257, place it in the 72nd percentile of all CPUs tested. This is a solid mid-range processor, but it is not in the same league as the high-end CPUs that would typically be paired with an RTX 4090.

In Doom, which is a fast-paced FPS that benefits from high IPC and strong single-thread performance, the i5-12400's single-core capabilities are adequate but not exceptional. The 3DMark single-thread score of 910 and the Passmark single-thread score of 3456 indicate that the processor can handle the game's primary thread reasonably well, but it struggles to keep up with the GPU's frame generation at lower resolutions. The 12 threads are sufficient for the game's multi-threaded aspects, but Doom is not a heavily threaded title, so the CPU's core count is less important than its clock speed and IPC.

The nearest rivals to the i5-12400, based on average benchmark scores, include the AMD EPYC 7643 (deltaPct -0.1), Intel Core i7-1355U (deltaPct -0.3), AMD Ryzen AI 5 330 (deltaPct -0.7), and Intel Core i3-14100F (deltaPct 0.9). These comparisons show that the i5-12400 is in a competitive performance tier, but none of these processors are known for being top-tier gaming CPUs. The data suggests that the CPU is the limiting factor in this combo, particularly at 1080p, where the frame rates are capped well below what the RTX 4090 could theoretically produce.

The CPU's 18 MB of shared L3 cache and 1.25 MB per-core L2 cache provide adequate memory latency for gaming, but the processor's overall performance is constrained by its 65W TDP and the fact that it is not unlocked for overclocking. The benchmark results show a Passmark multithread score of 18747, which is respectable, but the single-thread performance is what matters most for Doom. The data indicates that this CPU is a capable partner for the RTX 4090 at 1440p and 4K, but it is not a perfect match for maximizing the GPU's potential at 1080p.

FAQ

Q: Is the Intel Core i5-12400 a bottleneck for the RTX 4090 in Doom?

A: Yes, particularly at 1080p. The data shows that at 1080p Low, the combo achieves 363 FPS, but at 4K Low it achieves 156 FPS. The relatively small gap between Low and Ultra at 1080p (96 FPS) compared to 4K (62 FPS) indicates that the CPU is limiting performance more at lower resolutions.

Q: What resolution provides the best balance between CPU and GPU utilization?

A: The 1440p results are the most balanced, with frame rates ranging from 173 FPS at Ultra to 287 FPS at Low. This suggests that both the CPU and GPU are being used effectively, and the system is not overly constrained by either component.

Q: How does this combo rank compared to other tested systems?

A: The combo ranks 158th out of 3712 tested configurations, placing it in the top 4.3% of all systems tested for Doom. This is a strong result, but it is not at the very top, which is likely reserved for systems with higher-end CPUs.

Q: What is the best settings preset for 4K gaming?

A: The data shows that 4K Ultra produces 94 FPS, which is playable, but 4K Medium produces 136 FPS with a minimum of 115 FPS. For a smoother experience, the Medium preset at 4K offers a better balance of visual quality and frame rate.

Q: Is the RTX 4090 being fully utilized at 1080p?

A: No, the data suggests it is not. At 1080p Low, the system produces 363 FPS, but this is likely limited by the CPU's frame generation speed. The RTX 4090 is capable of much higher frame rates, but the CPU prevents it from reaching its full potential.

Q: What is the minimum FPS for the 1080p Medium preset?

A: The measured data shows a minimum FPS of 294 and a maximum of 397, with an average of 345 FPS. This indicates that frame pacing is stable, but the minimum is still high enough for smooth gameplay.

Measured FPS Breakdown

At 1920x1080, the system delivers its highest raw frame rates. The Low preset produces an average of 363 FPS, which is the highest measured in this configuration. The Medium preset averages 345 FPS, with a minimum of 294 and a maximum of 397, showing a stable frame rate range. The High preset averages 326 FPS, and the Ultra preset averages 267 FPS. These numbers indicate that the CPU is the limiting factor, as the difference between Low and Ultra is only 96 FPS, which is a relatively small range given the GPU's power.

At 2560x1440, the frame rates are more moderate but still very high. The Low preset averages 287 FPS, the Medium preset averages 250 FPS with a minimum of 213 and a maximum of 288, the High preset averages 211 FPS, and the Ultra preset averages 173 FPS. The difference between Low and Ultra is 114 FPS, which is slightly larger than at 1080p, suggesting that the GPU is beginning to take on more of the workload. This resolution offers the best balance between visual quality and performance, with even the Ultra preset being well above the 144 Hz refresh rate of most high-end monitors.

At 3840x2160, the system's performance drops significantly, but remains playable. The Low preset averages 156 FPS, the Medium preset averages 136 FPS with a minimum of 115 and a maximum of 156, the High preset averages 115 FPS, and the Ultra preset averages 94 FPS. The difference between Low and Ultra is 62 FPS, which is the smallest absolute gap across all resolutions. This indicates that the GPU is now the primary bottleneck, as the higher pixel count demands more from the RTX 4090's memory bandwidth and shading units. The 4K Medium preset, with its 136 FPS average, is the best option for high-refresh-rate 4K gaming, while the Ultra preset is best suited for 60 FPS gaming with maximum visuals.

How This Combo Ranks

The Intel Core i5-12400 and NVIDIA GeForce RTX 4090 combination ranks 158th out of 3712 tested combos in Doom, placing it in the top 4.3% of all systems. This is an impressive ranking, but it is important to note that the rank is likely held back by the CPU's performance at lower resolutions. The RTX 4090 is a top-tier GPU, placing in the 88th percentile of all GPUs, with an average benchmark score of 60347. Its nearest rivals in terms of average score are the Intel Arc Pro A60 (deltaPct 0), AMD Radeon Pro Vega 48 (deltaPct 0.3), AMD Radeon Pro W6600M (deltaPct -2.5), and AMD Radeon PRO V710 (deltaPct 2.9), which are all professional or workstation cards, highlighting the 4090's consumer gaming focus.

The CPU, in contrast, places in the 72nd percentile of all CPUs, with an average benchmark score of 18683. Its nearest rivals, such as the AMD EPYC 7643 (deltaPct -0.1) and Intel Core i7-1355U (deltaPct -0.3), are not typically associated with high-end gaming. This discrepancy between the GPU's high ranking and the CPU's mid-range ranking suggests that the combo's overall rank of 158 is a result of the GPU's dominance, but it is not as high as it could be with a more powerful CPU.

The data shows that the combo performs best at 1440p, where the frame rates are high enough to take advantage of high-refresh-rate monitors, and the CPU is not as much of a limiting factor as it is at 1080p. The 4K performance is also strong, with the Ultra preset still hitting 94 FPS, but the system is clearly not optimized for maximum frame rates at that resolution. Overall, this combo ranks well, but it confirms the RTX 4090's raw power rather than a balanced system.

Settings Recommendations

For 1080p gaming, the data suggests that the CPU is the limiting factor, so there is little benefit to using the Ultra preset over the High preset. The High preset averages 326 FPS, while the Ultra preset averages 267 FPS, a difference of 59 FPS. Since the CPU is already maxed out, the lower settings do not provide a significant frame rate increase, and the visual quality is better on High. The Medium preset, with its 345 FPS average, offers a marginal improvement over High, but the visual difference is likely not worth the loss in fidelity. For competitive play, the Low preset at 363 FPS is the best choice, but for most users, High is the sweet spot.

At 1440p, the Ultra preset averages 173 FPS, which is still well above the 144 Hz refresh rate of most gaming monitors. This makes the Ultra preset the clear recommendation for this resolution, as it provides the best visual quality without sacrificing performance. The High preset, at 211 FPS, is also a good option for players with 240 Hz monitors, but the visual difference between High and Ultra is significant enough that most users will prefer Ultra. The Medium preset, at 250 FPS, is only recommended for players with extremely high refresh rate displays who prioritize frame rate over visuals.

For 4K gaming, the Ultra preset produces 94 FPS, which is playable but not ideal for high-refresh-rate displays. The Medium preset, with an average of 136 FPS and a minimum of 115 FPS, is the best balance of visual quality and performance, offering a smooth experience on 120 Hz displays. The High preset, at 115 FPS, is also a good option, but the Medium preset provides a more consistent frame rate. The Low preset, at 156 FPS, is only recommended for players who prioritize frame rate above all else, but the visual downgrade is substantial. Based on the measured data, the Medium preset at 4K is the best overall choice for this system, as it provides a high frame rate without significant visual compromises.