Doom

The Intel Core i5-9400 paired with the AMD Radeon RX 6600 XT delivers a highly playable experience in Doom, with the data showing a clear shift in system bottlenecks as resolution increases. At 1080p, the combination produces triple-digit frame rates across all tested settings, but the scaling to 1440p and 4K reveals the GPU’s increasing dominance as the primary limiting factor. This analysis breaks down the measured performance, contextualizes the combo’s standing, and interprets how the components’ specifications align with the observed results.

Resolution Scaling

The measured FPS data shows a predictable yet informative degradation as resolution climbs from 1920x1080 to 3840x2160. At the High preset, the average frame rate drops from 143.8 FPS at 1080p to 92.9 FPS at 1440p, a reduction of roughly 35%. Moving further to 4K, the average falls to 48.4 FPS, which represents a 66% decline from the 1080p result. This steep drop-off strongly indicates that the AMD Radeon RX 6600 XT is the limiting component at higher resolutions, as the workload becomes increasingly pixel-bound.

The scaling pattern across all settings reinforces this interpretation. At Low settings, the 1080p average of 192.9 FPS falls to 125.4 FPS at 1440p and then to 69.1 FPS at 4K. The percentage losses are similar regardless of preset, suggesting that the GPU’s computational throughput, rather than the CPU’s frame-generation capability, dictates the ceiling once resolution increases. The gap between 1440p and 4K is consistently larger than the gap between 1080p and 1440p, which aligns with the quad-pixel count jump to 3840x2160.

Notably, the Ultra preset shows the most severe scaling, with 116.1 FPS at 1080p dropping to 77 FPS at 1440p and then to 41.8 FPS at 4K. The 4K Ultra result falls below the 60 FPS threshold, indicating that this combination cannot sustain smooth gameplay at maximum settings in 4K. The data implies that for 4K gaming, even Medium settings (57.9 FPS) barely breach playability, while High (48.4 FPS) and Ultra (41.8 FPS) fall short.

How This Combo Ranks

The combination of the Intel Core i5-9400 and AMD Radeon RX 6600 XT ranks 1154 out of 1681 tested combos for Doom. This places it in the lower third of all pairings, which is somewhat surprising given the GPU’s individual performance level. The RX 6600 XT sits in the 71st percentile of all GPUs based on average benchmark scores, while the i5-9400 falls in the 50th percentile of all CPUs. The combo’s mid-pack ranking suggests that the CPU, while not weak, holds back the GPU in this specific game’s workload.

Comparing the GPU to its nearest rivals provides context. The RX 6600 XT’s average benchmark score of 27985 is just 0.1% higher than the NVIDIA GeForce GTX 980 Ti (27956) and 0.4% higher than the AMD Radeon R9 M395X (27883). It trails the NVIDIA GeForce RTX 3070 by 0.9% (28238) and the AMD FirePro S7150 by 1.5% (28409). These margins are razor-thin, indicating that the RX 6600 XT performs essentially on par with these competitors in synthetic benchmarks.

The CPU’s nearest rivals show a similar clustering. The i5-9400’s average score of 2305 is a mere 0.2% above the Intel Core i3-10305 (2300) and Intel Core i3-1125G4 (2299), and 0.4% above the Intel Xeon E-2134 (2295). It slightly trails the Intel Core i7-8809G by 0.6% (2319). This tight grouping suggests the i5-9400 is competitive with these alternatives, but none of them represent a significant upgrade path.

GPU Role

The AMD Radeon RX 6600 XT is built on the RDNA 2.0 architecture with the Navi 23 chip, manufactured on a 7 nm process by TSMC. It contains 11,060 million transistors on a 237 mm² die, with 2048 shading units, 128 texture mapping units, and 64 render output units. The GPU operates with a base clock of 1968 MHz, a game clock of 2359 MHz, and a boost clock of 2589 MHz. These clock speeds are relatively high, which helps explain the card’s strong performance at 1080p where the pixel workload is lighter.

Memory configuration plays a critical role in the observed scaling. The card has 8 GB of GDDR6 memory on a 128-bit bus, delivering 256.0 GB/s of bandwidth. At 4K, the larger frame buffer demands and higher resolution textures place greater strain on this bandwidth. The fact that average FPS drops to 48.4 at High settings in 4K suggests the memory subsystem, rather than raw compute, may be a limiting factor at that resolution. The effective memory speed of 16 Gbps is decent, but the narrow 128-bit bus constrains overall throughput compared to wider-memory rivals.

The GPU’s compute capabilities are substantial, with an FP32 throughput of 10.60 TFLOPS and a pixel rate of 165.7 GPixel/s. These specifications support the high frame rates seen at 1080p, where the card delivers 143.8 FPS on High settings. The texture rate of 331.4 GTexel/s also contributes to maintaining smooth performance in Doom’s fast-paced environments. The card supports DirectX 12 Ultimate, which aligns with Doom’s modern rendering requirements.

Measured FPS Breakdown

At 1920x1080, the combination performs exceptionally well across all presets. Low settings produce an average of 192.9 FPS, Medium reaches 169.9 FPS, High achieves 143.8 FPS, and Ultra still manages 116.1 FPS. All of these results exceed the typical 60 FPS target by a wide margin, making 1080p gaming on any preset a smooth experience. The spread from Low to Ultra is 76.8 FPS, indicating that settings have a significant impact but never compromise playability.

Moving to 2560x1440, the averages remain strong but show the GPU beginning to strain. Low settings yield 125.4 FPS, Medium drops to 105.5 FPS, High falls to 92.9 FPS, and Ultra settles at 77 FPS. Even at the most demanding preset, the framerate stays above 60 FPS, making 1440p viable for competitive play or visually rich single-player sessions. The relative consistency across settings suggests the GPU still has headroom at this resolution.

At 3840x2160, the situation changes dramatically. Low settings produce 69.1 FPS, which is playable, but Medium drops to 57.9 FPS, High falls to 48.4 FPS, and Ultra bottoms out at 41.8 FPS. Only the Low preset maintains a comfortable framerate, while Medium barely crosses the 60 FPS threshold. High and Ultra fail to reach playable levels, indicating that 4K gaming requires substantial settings reductions with this hardware.

Settings Recommendations

For 1080p gaming, the data supports using Ultra settings without hesitation. The 116.1 FPS average at this preset far exceeds the refresh rate of most standard monitors, and the visual quality benefits are substantial. Even if a gamer prefers maximum smoothness, dropping to High (143.8 FPS) or Medium (169.9 FPS) offers diminishing returns in playability but notable gains in frame rate.

At 1440p, High settings at 92.9 FPS represent an excellent balance between visual fidelity and performance. The jump to Ultra (77 FPS) still maintains a playable framerate, but the 15.9 FPS loss may not justify the additional graphical load. For gamers prioritizing higher refresh rates, Medium (105.5 FPS) or Low (125.4 FPS) provide smoother motion without sacrificing too much detail.

For 4K gaming, the choices are constrained by the hardware’s limits. Low settings at 69.1 FPS is the only preset that delivers a consistently smooth experience. Medium at 57.9 FPS is borderline, and some players might tolerate the occasional dips below 60 FPS. High (48.4 FPS) and Ultra (41.8 FPS) are not recommended for fast-paced gameplay, as the reduced frame rates could impair responsiveness.

CPU Role

The Intel Core i5-9400 is a 6-core, 6-thread processor based on the Coffee Lake architecture, manufactured on a 14 nm process. It has a base clock of 2.90 GHz and a boost clock of 4.10 GHz, with a 65 W TDP. The CPU’s cache hierarchy includes 64 KB of L1 per core, 256 KB of L2 per core, and 9 MB of shared L3 cache. This configuration provides solid single-thread performance, as evidenced by its Cinebench R23 single-core score of 1125.

In Doom, which is a well-optimized game that scales across multiple cores, the i5-9400’s 6 cores and 6 threads are sufficient to avoid becoming a bottleneck at lower resolutions. The data supports this: at 1080p High, the combo delivers 143.8 FPS, which is well above what the GPU alone would produce if CPU-limited. The boost clock of 4.10 GHz helps maintain high frame rates in scenes with complex geometry or numerous enemies.

However, the CPU’s relatively modest multi-core performance, reflected in its Cinebench R23 multi-core score of 7969, may limit the system in CPU-intensive scenarios. The combo’s rank of 1154 out of 1681 in Doom suggests that the i5-9400 holds back the RX 6600 XT compared to pairings with faster processors. The 50th percentile ranking among all CPUs indicates it is an average performer, but not a top-tier option for maximizing frame rates in demanding titles.

FAQ

Q: What is the average FPS at 1080p with High settings?

A: The measured average FPS is 143.8 at 1920x1080 with High settings.

Q: Can this combo handle 4K gaming?

A: Only at Low settings, which produces 69.1 FPS. Medium settings yield 57.9 FPS, while High (48.4 FPS) and Ultra (41.8 FPS) fall below playable thresholds.

Q: How does the RX 6600 XT compare to the RTX 3070 in average benchmark score?

A: The RX 6600 XT’s average score of 27985 is 0.9% lower than the RTX 3070’s 28238.

Q: What is the boost clock of the Intel Core i5-9400?

A: The boost clock is 4.10 GHz.

Q: How much VRAM does the RX 6600 XT have?

A: It has 8 GB of GDDR6 memory.

Q: What is the combo’s rank among all tested configurations in Doom?

A: It ranks 1154 out of 1681 tested combos.