Doom

The Intel Core i5-9400 is a six-core, six-thread desktop processor from the Coffee Lake family, running at a 2.90 GHz base clock and a 4.10 GHz boost clock. With a 65W TDP and 9 MB of shared L3 cache, this CPU sits in the middle of the pack historically, holding a 50th percentile ranking among all tested processors. Its average benchmark score of 2305 places it within a hair of rivals like the Intel Core i3-10305 and Intel Core i3-1125G4, which score 2300 and 2299 respectively—a delta of just 0.2% in both cases. In a fast-paced FPS like Doom, the 4.10 GHz boost clock is the more relevant figure, as the game’s single-threaded rendering paths benefit from higher frequencies. The 6-core/6-thread layout is adequate for the game’s engine, which was released in 2016 and does not rely heavily on many threads. The CPU’s performance here is sufficient to feed the GPU without becoming a severe bottleneck at most settings, though the data suggests that at lower resolutions and higher frame rates, the CPU’s limitations become more apparent.

Settings Recommendations

The measured FPS rows show a clear pattern: the "Low" preset consistently delivers the highest average frame rates across all resolutions, but it does so at the cost of visual fidelity. At 1920x1080, the Low preset averages 254.4 FPS, while High averages 218 FPS, a difference of 36.4 FPS. Moving to 2560x1440, Low averages 193.7 FPS versus High’s 138.8 FPS, a gap of 54.9 FPS. At 3840x2160, the Low preset still manages 104.9 FPS, compared to High’s 78.8 FPS. The "Ultra" preset is the most demanding, dropping to 61.4 FPS at 4K, which is below the 78.8 FPS of High. For a game like Doom, which rewards high frame rates for smooth aiming and reaction, the Medium preset offers a strong balance. At 1080p, Medium averages 240.4 FPS, only 14 FPS behind Low, while providing better visual quality. At 1440p, Medium averages 169.8 FPS, which is still well above the 144 Hz refresh rate of many monitors, and at 4K, Medium averages 89.5 FPS, which is comfortably playable. The Ultra preset, while visually richer, costs a significant frame rate penalty—at 1080p, it drops to 178.8 FPS, a 61.6 FPS loss compared to Medium. The data suggests that Medium is the sweet spot for this combo, as it keeps frame rates high enough for competitive play while preserving enough graphical detail for an immersive experience.

Resolution Scaling

The FPS drop from 1080p to 4K reveals how the workload shifts between the CPU and GPU. From 1920x1080 to 2560x1440, the average FPS across all settings drops by roughly 30-40%—for instance, High goes from 218 to 138.8 FPS, a reduction of 79.2 FPS. From 1440p to 4K, the drop is even steeper: High falls from 138.8 to 78.8 FPS, a 60 FPS loss. This scaling indicates that the AMD Radeon RX 9070 is the primary limiting factor as resolution increases, since the pixel count quadruples from 1080p to 4K, putting more pressure on the GPU’s rendering capabilities. At 1080p, the CPU is more involved, as the high frame rates (254.4 FPS on Low) approach the limits of what the i5-9400 can feed. The 4.10 GHz boost clock helps, but the 6-thread design means that at very high FPS, the CPU can become a bottleneck. At 4K, however, the GPU’s workload dominates, and the CPU has more headroom. The data shows that the RX 9070’s 16 GB of GDDR6 memory and 644.6 GB/s bandwidth are sufficient to handle the texture and geometry loads at 4K, but the frame rates at Ultra (61.4 FPS) suggest that the GPU’s compute throughput is the limiting factor at maximum settings.

How This Combo Ranks

In the database of tested CPU-GPU combinations for Doom, this pairing of the Intel Core i5-9400 and the AMD Radeon RX 9070 ranks 610th out of 1681 combos. This places it in the upper-middle tier of all tested systems, which is a strong result given the age of the CPU. The rank reflects the balance between the two components: the RX 9070 is a modern GPU with a 79th percentile ranking among all GPUs, while the i5-9400 is a mid-range processor from 2018. The combo’s performance is higher than the CPU’s 50th percentile ranking alone would suggest, indicating that the GPU is doing most of the heavy lifting. Compared to other combos, this setup delivers frame rates that are competitive with newer CPUs, but the CPU’s single-thread performance (benchmarked at 1125 in Cinebench R23) may hold back the GPU in CPU-bound scenarios, such as the 1080p Low preset. The rank of 610 means there are 609 combos that perform better, many of which likely pair the RX 9070 with a newer, faster processor, but the i5-9400 still manages to keep the system in the top 36% of all tested combos.

GPU Role

The AMD Radeon RX 9070 is the dominant component in this pairing, built on the RDNA 4.0 architecture with a Navi 48 chip on a 4nm process. It features 3584 shading units, 224 texture mapping units, and 128 raster operation units, with a boost clock of 2520 MHz and a game clock of 2070 MHz. The 16 GB of GDDR6 memory on a 256-bit bus provides 644.6 GB/s of bandwidth, which is more than enough for Doom’s 2016-era textures and geometry. The GPU’s raw compute performance is 36.13 TFLOPS, and it holds a 79th percentile ranking among all GPUs, with an average benchmark score of 34780. Its nearest rivals include the NVIDIA A2 (34866, delta -0.2%) and the NVIDIA Quadro GV100 (34677, delta 0.3%), indicating that the RX 9070 sits in a performance neighborhood with those cards. In Doom, the GPU’s role is to render the fast-paced action at high frame rates, and the measured FPS shows it excels at this. At 1080p Low, it hits 254.4 FPS, but the GPU’s potential is likely capped by the CPU at that point. At 4K Ultra, the GPU is taxed heavily, delivering 61.4 FPS, which shows that the RDNA 4.0 architecture can handle 4K but with a significant performance hit at maximum settings. The 220W TDP and 550W suggested PSU indicate that this is a power-hungry card, but the performance justifies the requirement.

Measured FPS Breakdown

The measured FPS data provides a complete picture of how this combo performs across resolutions and settings. At 1920x1080, the averages are: Low 254.4 FPS, Medium 240.4 FPS, High 218 FPS, and Ultra 178.8 FPS. This shows a steady decline as settings increase, with the largest drop occurring from High to Ultra (39.2 FPS). At 2560x1440, the averages are: Low 193.7 FPS, Medium 169.8 FPS, High 138.8 FPS, and Ultra 113.4 FPS. The drop from High to Ultra is 25.4 FPS, slightly less steep than at 1080p, suggesting the GPU is becoming more of a factor. At 3840x2160, the averages are: Low 104.9 FPS, Medium 89.5 FPS, High 78.8 FPS, and Ultra 61.4 FPS. Here, the Ultra preset falls below the 60 FPS threshold, making it less ideal for smooth gameplay, while High maintains a playable 78.8 FPS. Across all resolutions, the Low preset provides the highest frame rates, but the Medium preset offers the best compromise between visual quality and performance, with 240.4 FPS at 1080p, 169.8 FPS at 1440p, and 89.5 FPS at 4K. The data indicates that for a 144Hz monitor, Medium at 1440p is the optimal choice, while for 4K gaming, High settings are the practical ceiling for maintaining a smooth experience above 60 FPS.