Rust

The Intel Core i5-9400 and AMD Radeon RX 5700 XT pairing in Rust delivers a clear, predictable performance curve that shifts from CPU-limited at 1080p to firmly GPU-limited at 4K. The data shows a 1080p Low average of 135.7 FPS, which drops to 76.1 FPS at High—a 44% reduction from the lowest preset to the highest. At 1440p, the spread tightens: Low runs at 96 FPS, while High falls to 53.4 FPS. Moving to 4K exposes the GPU's limits more aggressively, with Low producing 57.1 FPS, Medium dropping to 37.5 FPS, and Ultra bottoming out at 25.5 FPS. The scaling pattern is consistent: each resolution step-down from 4K to 1440p roughly doubles the frame rate at the same settings, while the 1440p-to-1080p jump yields a smaller gain—about 1.4x. This suggests that at 1080p, the Core i5-9400's six threads begin to cap performance, especially at Low where the GPU is not the bottleneck.

Resolution Scaling

The FPS progression across resolutions reveals where the system's balance shifts. At 1080p Low, the combo hits 135.7 FPS, a figure that drops to 96 FPS at 1440p Low (a 29% decline) and then to 57.1 FPS at 4K Low (another 40% drop). This steep 4K penalty is classic GPU-bound behavior—the RX 5700 XT's 8 GB of GDDR6 and 448.0 GB/s bandwidth are being saturated. At High settings, the pattern is similar but more compressed: 76.1 FPS at 1080p, 53.4 FPS at 1440p, and 31 FPS at 4K. The delta between 1440p and 4K at High is 42%, almost identical to the Low preset's 40% drop, indicating the GPU is the limiting component at both settings. However, at 1080p, the gap between Low (135.7 FPS) and High (76.1 FPS) is 44%, while at 4K that same Low-to-High gap is only 45% (57.1 vs 31 FPS). The consistency of these percentages points to a system where the i5-9400's 2.90 GHz base and 4.10 GHz boost clocks are sufficient to feed the GPU at lower resolutions, but the RX 5700 XT's raw throughput—9.754 TFLOPS FP32—becomes the sole arbiter at 4K. The Ultra preset at 4K (25.5 FPS) is the only measured row below 30 FPS, confirming that 4K Ultra is not viable for this pairing.

GPU Role

The RX 5700 XT is the star at higher resolutions, but its performance ceiling is clear. With 2560 shading units, 160 TMUs, and 64 ROPs, the card's pixel rate of 121.9 GPixel/s and texture rate of 304.8 GTexel/s directly correlate with the FPS drops seen at 4K. The GPU's boost clock of 1905 MHz and game clock of 1755 MHz are typical for RDNA 1.0, but the 7 nm process and 10,300 million transistors don't rescue it from the 4K Ultra wall. The 8 GB VRAM is not the limiting factor here—Rust's textures at Ultra on 4K stay within that capacity, as evidenced by the 25.5 FPS average rather than a stutter-driven crash. The memory clock of 1750 MHz (14 Gbps effective) across a 256-bit bus yields 448.0 GB/s, which matches the 4K High result of 31 FPS—enough for playable but not smooth. Comparing to its nearest rivals, the RX 5700 XT's average benchmark score of 24731 sits 0.1% below the NVIDIA RTX A5000 Mobile (24763) and 0.3% above the Intel Arc A350M (24647). In Rust specifically, this positions the card as a mid-tier performer: it outpaces the RTX 5060 Mobile (24592) by 0.6% in synthetic tests, but the game's 4K Ultra result of 25.5 FPS shows that synthetic parity doesn't translate to playable frame rates at max settings.

How This Combo Ranks

This specific CPU-GPU pairing ranks 1253 out of 1717 tested combos in Rust, placing it in the 27th percentile of all configurations. That rank is lower than the GPU's individual percentile (68th among all GPUs) and the CPU's percentile (50th among all CPUs), indicating a synergy deficit—the i5-9400 holds back the RX 5700 XT more than the reverse. The combo's 1080p High result of 76.1 FPS is respectable, but the 4K Ultra result of 25.5 FPS drags the overall standing down. For context, a combo ranked in the top 25% would need to sustain above 60 FPS at 1440p High; this pairing achieves 53.4 FPS there, falling short. The rank suggests that while the GPU alone is a solid 68th-percentile component, the CPU's six threads and 9 MB shared L3 cache create a bottleneck that prevents the card from reaching its full potential in Rust's demanding simulation-heavy environments.

FAQ

Q: Can this combo run Rust at 1080p with high settings smoothly?

A: Yes. The data shows a 1080p High average of 76.1 FPS, which is above the 60 FPS threshold for smooth gameplay. The 1080p Ultra result of 57.1 FPS is also playable, though it dips below 60.

Q: What is the best resolution for this pairing?

A: 1440p offers the best balance. The 1440p High result of 53.4 FPS is below 60, but 1440p Medium hits 64.9 FPS. For a locked 60 FPS experience, 1080p Medium (91.7 FPS) or 1080p High (76.1 FPS) are the safest choices.

Q: Is the RX 5700 XT's 8 GB VRAM sufficient for Rust at 4K?

A: Yes, based on the measured data. The 4K Ultra average of 25.5 FPS indicates the GPU is compute-bound, not VRAM-bound. The 8 GB GDDR6 with 448.0 GB/s bandwidth is enough to hold the textures, but the card's 9.754 TFLOPS FP32 throughput cannot maintain playable frame rates.

Q: How does the i5-9400 compare to its closest rivals in synthetic benchmarks?

A: The i5-9400's average benchmark score is 2305, which is 0.2% above the Intel Core i3-10305 (2300) and 0.2% above the Intel Core i3-1125G4 (2299). It is 0.4% ahead of the Intel Xeon E-2134 (2295) but 0.6% behind the Intel Core i7-8809G (2319).

Q: Why is the 4K Low result (57.1 FPS) so much higher than 4K High (31 FPS)?

A: The 45% difference comes from the GPU's workload. At Low settings, the RX 5700 XT's 160 TMUs and 64 ROPs can process the reduced geometry and texture loads faster. The 4K Low result is nearly double the 4K High, showing that Rust's High preset adds significant shading and texture work that the card cannot handle at 4K resolution.

Q: Is this combo better suited for competitive play or visual fidelity?

A: The data favors competitive play. The 1080p Low result of 135.7 FPS and 1440p Low of 96 FPS provide high refresh rates. For visual fidelity, 1440p Medium (64.9 FPS) is the sweet spot—it offers better clarity than Low while staying above 60 FPS.

CPU Role

The Intel Core i5-9400's six cores and six threads are the limiting factor at lower resolutions. Its 2.90 GHz base clock and 4.10 GHz boost clock, paired with 9 MB of shared L3 cache, deliver a Cinebench R23 multi-core score of 7969 and single-core score of 1125. In Rust, which is known for heavy single-threaded simulation work, the CPU's 50th-percentile standing among all processors matters. At 1080p Low, the combo hits 135.7 FPS, but that's only 41% higher than the 4K Low result of 57.1 FPS—a smaller gain than what a stronger CPU would enable. The 1080p Ultra result of 57.1 FPS exactly matches the 4K Low result, which is telling: at 1080p Ultra, the i5-9400's six threads are fully occupied, capping the frame rate to the same level as the GPU-bound 4K Low scenario. The CPU's 65 W TDP and Coffee Lake architecture (14 nm process) are modest, but its memory bandwidth of 42.7 GB/s over dual-channel DDR4 is adequate for Rust's entity-heavy servers. Compared to its nearest rivals, the i5-9400's average score of 2305 is nearly identical to the i3-10305 (2300) and i3-1125G4 (2299), meaning the CPU is not a standout performer—it's a mainstream part that works well enough at 1080p but becomes the bottleneck when the GPU's 4K workload allows the CPU to stretch.

Settings Recommendations

For this pairing, the measured data points to 1440p Medium as the best overall experience. It delivers 64.9 FPS—above the 60 FPS threshold—while providing better visual quality than Low. At 1080p, Medium (91.7 FPS) is the recommended preset for players with high-refresh monitors, as it balances visual fidelity with a comfortable margin over 60 FPS. The 1080p High setting (76.1 FPS) is also viable for those who prioritize graphics over frame rate, but Ultra (57.1 FPS) dips below 60 and is not recommended. At 1440p, High (53.4 FPS) falls short of 60, so Medium is the ceiling for smooth play. For 4K, the data shows that Low (57.1 FPS) is the only playable preset—Medium (37.5 FPS), High (31 FPS), and Ultra (25.5 FPS) all fail to reach 30 FPS, making them unsuitable for anything but screenshots. The best strategy is to run 1440p Medium for a standard monitor, or 1080p Medium/High for esports-style play. Avoid 4K unless you're willing to accept Low settings, which still provide a playable 57.1 FPS but sacrifice most of Rust's visual detail.