Rust

Rust presents a demanding workload that scales significantly with resolution, and the measured data for the AMD Ryzen 9 8945HX and NVIDIA GeForce RTX 4090 combination shows a clear transition from a CPU-bound scenario at 1080p to a GPU-bound one at 4K. The performance curve indicates that while this pairing is exceptionally powerful, the RTX 4090 laptop GPU is the primary factor limiting frame rates at higher resolutions, whereas the 16-core processor provides ample headroom at lower settings.

Resolution Scaling

The frame rate drop from 1080p to 4K is steep and consistent, revealing the growing burden on the GPU as pixel count increases. At High settings, the average frame rate falls from 128 FPS at 1920x1080 to 88 FPS at 2560x1440, a 31% reduction, and then to 52 FPS at 3840x2160, a 59% reduction from the 1080p baseline. This scaling pattern is typical for a game like Rust, where the GPU’s rendering load—driven by the RTX 4090’s 16384 shading units and 176 ROPs—becomes the dominant constraint as resolution climbs.

The trend is similar across all settings. On Low settings, the average FPS drops from 226 at 1080p to 156 at 1440p and 92 at 4K. The 1080p Low result of 226 FPS is particularly telling: it suggests the CPU is nearing its limit, as the GPU is capable of far higher output in lighter scenes, but the Ryzen 9 8945HX’s 5.40 GHz boost clock and 32 threads are still able to push frame rates well beyond what most displays can show. At Medium settings, the averages are 152 FPS at 1080p, 105 FPS at 1440p, and 62 FPS at 4K, with the 4K figure including a minimum of 52 FPS and a maximum of 71 FPS, indicating some variability in demanding scenes.

Ultra settings present the heaviest load, with averages of 98 FPS at 1080p, 67 FPS at 1440p, and just 40 FPS at 4K. The gap between 1440p and 4K at Ultra is a 40% drop, which is slightly less severe than the 59% drop seen at High, suggesting that at Ultra, the GPU is already saturated at lower resolutions and the incremental cost of 4K is proportionally smaller. Overall, the data shows that 1080p and 1440p are the sweet spots for high refresh rate gameplay, while 4K requires dropping settings to maintain playable frame rates, with Low delivering 92 FPS and Medium delivering 62 FPS.

GPU Role

The NVIDIA GeForce RTX 4090 is the decisive component in this pairing for determining absolute frame rates, particularly at 1440p and 4K. Its 24 GB of GDDR6X memory on a 384-bit bus provides a 1.01 TB/s bandwidth, which is essential for Rust’s large world textures and asset streaming at high resolutions. The data supports this: at 4K Ultra, the average FPS of 40 is the lowest recorded, and while the CPU is not idle, the GPU’s pixel rate of 443.5 GPixel/s and texture rate of 1,290.2 GTexel/s are the bottlenecks. The GPU’s 82.58 TFLOPS of FP32 performance is a theoretical peak, but the measured results show that even this flagship mobile part cannot maintain 60 FPS at 4K Ultra, underscoring the game’s intensity.

The GPU’s clock behavior, with a base of 2235 MHz and a boost of 2520 MHz, is consistent with the performance scaling seen in the measured rows. At 1080p Low, the 226 FPS average suggests the GPU is not fully utilized, as the CPU becomes the limiting factor. However, as resolution increases, the GPU’s role expands. The 4K Medium result of 62 FPS, with a minimum of 52 FPS, shows that the RTX 4090 is working hard, but the 24 GB frame buffer prevents any memory capacity issues, even at 4K with Ultra textures. The GPU’s percentile rank of 88 among all GPUs and its Passmark G3D score of 38194 place it well above the average, but its nearest rivals in the benchmark database, such as the Intel Arc Pro A60 with a delta of 0%, are not representative of its gaming performance in Rust.

The RTX 4090’s 128 RT cores and 512 tensor cores are not directly exercised by the measured FPS data, but they contribute to the overall feature set. The GPU’s 88th percentile ranking indicates that it is a high-end part, yet the 4K Ultra average of 40 FPS shows that Rust can stress even this hardware. The data suggests that for 4K gaming, users should expect to use Medium settings (62 FPS) or Low (92 FPS) to avoid the sub-60 FPS territory of High (52 FPS) and Ultra (40 FPS). The GPU’s memory bandwidth of 1.01 TB/s is a key asset, as it allows the 24 GB frame buffer to feed the 16384 shading units efficiently, but it is not enough to overcome the raw compute demand of 4K Ultra.

CPU Role

The AMD Ryzen 9 8945HX provides the computational foundation for this system, and its influence is most apparent at 1080p with lower settings. With 16 cores and 32 threads based on the Zen 4 architecture, this mobile processor has a base clock of 2.50 GHz and a boost clock of 5.40 GHz, which allows it to handle Rust’s simulation and entity logic. The CPU’s benchmark scores are strong, with a Cinebench R23 multi-core score of 42713 and a single-core score of 6030, placing it in the 95th percentile of all CPUs. Its nearest rival, the Intel Core Ultra 9 285HX, has an average score of 76155, a mere 0.1% delta, indicating that these two processors are virtually tied in general compute.

In Rust, the CPU’s role is to process the game’s server-side logic, player interactions, and world events, which is heavily multithreaded. The 1080p Low average of 226 FPS is a direct indicator of CPU headroom, as the GPU could likely render more frames if the CPU could feed it faster. The 1080p Medium result of 152 FPS and High result of 128 FPS show a progression where the GPU starts to take on more work, but the CPU is still providing enough throughput to keep frame rates above 120 FPS. The 1080p Ultra average of 98 FPS, however, suggests that the CPU is not the bottleneck at this setting; the GPU’s workload is the limiting factor.

The CPU’s 64 MB of L3 cache is beneficial for Rust’s memory access patterns, and the dual-channel DDR5 memory support with 83.2 GB/s bandwidth provides sufficient data transfer for the 32 threads. The benchmark data shows that the Ryzen 9 8945HX is within 0.6% of the AMD Ryzen 9 9950X3D in average score, which is noteworthy because the 9950X3D has a reputation for gaming performance. However, in Rust, the 8945HX’s high boost clock of 5.40 GHz is a critical factor, as the game’s frame rate at 1080p Low is well above 200 FPS, indicating that single-thread performance is strong. The CPU’s Passmark single-thread score of 3907 confirms this, and its 95th percentile rank among all CPUs means it outperforms the vast majority of processors, including its nearest rivals.

The CPU’s 55 W TDP is a mobile-oriented figure, but the performance delivered suggests efficient power scaling. The measured FPS data does not show a scenario where the CPU is the sole bottleneck at higher resolutions; at 4K, the GPU is clearly the limit. However, the 1080p results demonstrate that the Ryzen 9 8945HX is well-suited to esports-level frame rates in Rust, with the 226 FPS Low average being the highest recorded in any configuration. This indicates that for competitive play, this CPU-GPU combo can deliver frame rates far beyond the refresh rate of most monitors, provided the GPU is not overloaded.

FAQ

Q: What is the highest average frame rate achieved in Rust with this CPU-GPU combo?

A: The highest average frame rate is 226 FPS, achieved at 1920x1080 with Low settings.

Q: Can this system maintain 60 FPS at 4K resolution in Rust?

A: Yes, but only on Low settings, which delivers an average of 92 FPS. Medium settings average 62 FPS, while High and Ultra fall below 60 FPS at 52 and 40 FPS, respectively.

Q: How does the CPU compare to its closest rival in general benchmarks?

A: The AMD Ryzen 9 8945HX has an average benchmark score of 76212, which is 0.1% higher than the Intel Core Ultra 9 285HX (76155) and 0.6% higher than the AMD Ryzen 9 9950X3D (75779).

Q: What is the performance difference between 1080p and 1440p at High settings?

A: The average FPS drops from 128 at 1080p to 88 at 1440p, a 31% reduction.

Q: Is the GPU or CPU the limiting factor at 4K Ultra settings?

A: The GPU is the limiting factor. The 4K Ultra average of 40 FPS is a result of the RTX 4090 being saturated, while the CPU has sufficient headroom to process the game logic.

Q: What is the lowest frame rate recorded in the measured data?

A: The lowest average is 40 FPS at 3840x2160 with Ultra settings. The lowest minimum FPS recorded is 52 FPS, which occurs at 4K Medium settings.

Settings Recommendations

For the best balance of visual fidelity and performance, Medium settings at 1440p are the recommended choice, as they deliver an average of 105 FPS with a minimum of 89 FPS, ensuring smooth gameplay without major dips. This configuration provides a 19% boost over High settings at the same resolution (88 FPS) while still offering a substantial improvement over Low (156 FPS) in visual quality. At 1080p, Medium settings at 152 FPS are ideal for high refresh rate monitors, while High settings at 128 FPS are also viable for a more visually rich experience.

For 4K gaming, the data suggests that Low settings are the only option for a consistently high frame rate, with an average of 92 FPS. Medium settings at 4K average 62 FPS, which is playable but may suffer from occasional dips to 52 FPS, as indicated by the minimum FPS. High and Ultra settings at 4K are not recommended for competitive play, as they drop to 52 and 40 FPS, respectively, which can impact responsiveness. The Ultra preset is best avoided unless visual quality is the absolute priority and the user can tolerate sub-50 FPS gameplay. Overall, the measured data indicates that this system excels at 1080p and 1440p, where it can leverage the CPU’s strength, and that 4K requires a significant settings compromise.

Measured FPS Breakdown

At 1920x1080, the system delivers its highest frame rates. Low settings produce an average of 226 FPS, which is the peak performance recorded. Medium settings average 152 FPS, with a minimum of 129 FPS and a maximum of 175 FPS. High settings average 128 FPS, and Ultra settings average 98 FPS. This resolution is clearly CPU-bound, as the GPU has ample headroom to render frames at these rates.

At 2560x1440, the frame rates scale down as the GPU takes on more work. Low settings average 156 FPS, which is a 31% drop from 1080p Low. Medium settings average 105 FPS, with a minimum of 89 FPS and a maximum of 120 FPS. High settings average 88 FPS, and Ultra settings average 67 FPS. This resolution offers a good balance, with Medium and High providing smooth experiences.

At 3840x2160, the GPU is the dominant constraint. Low settings average 92 FPS, making it the only preset above 60 FPS. Medium settings average 62 FPS, with a minimum of 52 FPS and a maximum of 71 FPS. High settings average 52 FPS, and Ultra settings average 40 FPS. The 4K results highlight the RTX 4090’s limits in Rust, with only Low settings providing a comfortable margin above 60 FPS, while Medium is marginal and High/Ultra are below the threshold for smooth gameplay.