Rust

Resolution Scaling — how FPS drops from 1080p to 4K and what it says about the limiting component

The measured FPS data for Rust with the AMD Ryzen 9 8945HX and AMD Radeon 890M reveals a steep performance cliff as resolution climbs. At 1920x1080 with Low settings, the combo averages 68 FPS. Dropping to 2560x1440 Low yields 47 FPS, a 31% reduction. Pushing further to 3840x2160 Low produces only 28 FPS, a 59% decline from the 1080p baseline. This scaling pattern is not linear — the gap between 1440p and 4K (40% drop) is steeper than the gap between 1080p and 1440p (31% drop). The data strongly indicates that the integrated GPU becomes the primary bottleneck at higher resolutions, as pixel throughput requirements outpace what the Radeon 890M can deliver.

The High preset tells a similar story with even harsher penalties. At 1080p High, the system manages 38 FPS; at 1440p High it falls to 26 FPS (32% loss); and at 4K High it collapses to 16 FPS (58% loss from 1080p). Notably, the 4K High result of 16 FPS is below the 4K Medium average of 19 FPS, suggesting that the transition from Medium to High at 4K imposes a massive fill-rate burden. The gap between Low and High at 4K is only 12 FPS (28 vs 16), whereas at 1080p the same settings gap is 30 FPS (68 vs 38). This compression of performance across settings at 4K is a classic sign that the GPU is saturated — no amount of graphical detail reduction can compensate for the raw pixel count.

Looking at the Medium preset, which includes min/max data, the trend persists. At 1080p Medium, the average is 46 FPS with a range of 39-52. At 1440p Medium, the average drops to 31 FPS (27-36 range). At 4K Medium, the average falls to 19 FPS (16-21 range). The min FPS values at each resolution are telling: 39 at 1080p, 27 at 1440p, and 16 at 4K. These floor values suggest that even in less demanding scenes, the 4K experience will frequently dip below 20 FPS, which is generally considered unplayable for a survival game requiring quick reactions.

The Ultra preset is almost academic at this point. At 1080p Ultra, the system produces 29 FPS; at 1440p Ultra, 20 FPS; and at 4K Ultra, a mere 12 FPS. The gap between Low and Ultra at 1080p is 39 FPS (68 vs 29), but at 4K it shrinks to 16 FPS (28 vs 12). This narrowing delta further confirms that the GPU's shading units, TMUs, and ROPs are the limiting factor — the 32 ROPs and 64 TMUs on the 890M simply cannot keep up with 4K's 8.3 million pixels regardless of how much load is offloaded by lowering quality settings.

GPU Role — VRAM, clocks, and how they relate to this game's results

The AMD Radeon 890M is an integrated graphics processor built on the RDNA 3.5 architecture, fabricated on a 4 nm process at TSMC. Its memory configuration is "System Shared" — meaning it borrows from the system's DDR5 RAM rather than having dedicated VRAM. The memory bus width is also "System Shared," and bandwidth is listed as "System Dependent," which makes the 890M's performance heavily contingent on the host platform's memory subsystem. In Rust, a game known for frequent asset streaming and large world maps, this shared memory arrangement can create contention between the CPU and GPU for bandwidth. The Ryzen 9 8945HX supports dual-channel DDR5 with a measured bandwidth of 83.2 GB/s, which is shared between the 16 cores and the iGPU. When both are under load — which Rust demands — the memory bandwidth becomes a contested resource.

The GPU's clock behavior is notable. The base clock is 400 MHz, but the boost clock reaches 2900 MHz. This is a massive dynamic range, and the actual sustained clock will depend on thermal headroom and power allocation within the mobile platform. The TDP is listed at 15 W, which is extremely low for the performance being asked. At 1080p Low, the 890M manages 68 FPS, which is respectable for an integrated solution. However, the 15 W power envelope explains why higher resolutions cause such dramatic frame rate collapses — the GPU cannot sustain high clocks when pixel throughput demands increase. The boost clock of 2900 MHz likely only holds for short bursts; sustained loads at 4K would cause clock throttling, exacerbating the FPS drops.

The compute specifications are telling: 1024 shading units, 64 TMUs, 32 ROPs, and 16 ray tracing cores. The FP32 throughput is 5.939 TFLOPS, which places the 890M in the entry-level discrete GPU territory. The pixel rate is 92.80 GPixel/s and texture rate is 185.6 GTexel/s. For Rust, which uses deferred rendering and has significant overdraw from vegetation and building structures, the 32 ROPs become a bottleneck at higher resolutions. At 4K, the pixel rate requirement is roughly 33 MPixel/s at 60 FPS, but the 890M's theoretical peak is 92.80 GPixel/s — yet the measured 4K results (12-28 FPS across presets) show that theoretical peak is never approached in real-world conditions. The gap between theoretical and measured performance is common for integrated GPUs, as they must share power and thermal budgets with the CPU.

The benchmark scores for the 890M provide context. Its PassMark G3D score is 8076, and its percentile ranking versus all GPUs is 45, meaning it sits slightly below the median. Its nearest rivals include the AMD Radeon Vega 8 (avgScore 9221, deltaPct -0.1), NVIDIA GeForce GTX 960 (avgScore 9273, deltaPct -0.7), NVIDIA GeForce GTX 465 (avgScore 9294, deltaPct -0.9), and NVIDIA GeForce GTX 850M (avgScore 9302, deltaPct -1). The deltaPct values are all negative, indicating the 890M scores slightly lower than these competitors. This places the 890M in the same performance class as a GTX 960, which was a mid-range discrete GPU from a decade ago. In Rust, this means the 890M can handle 1080p gaming at playable frame rates but struggles beyond that.

CPU Role — cores, clocks, and how they relate to this game's results

The AMD Ryzen 9 8945HX is a 16-core, 32-thread processor based on the Zen 4 architecture, codenamed Dragon Range. It operates at a base clock of 2.50 GHz and boosts up to 5.40 GHz. The TDP is 55 W, which is modest for a 16-core mobile chip, but the boost clock suggests it can draw more power under load. The cache hierarchy is generous: 64 KB L1 per core, 1 MB L2 per core, and 64 MB L3 total. This large L3 cache is beneficial for Rust, which involves complex world simulation, entity tracking, and physics calculations that benefit from cached data.

The CPU's benchmark results are impressive. In Cinebench R23, it scores 42713 multicore and 6030 single-core. The PassMark multithread score is 51405, and single-thread is 3907. The percentile ranking versus all CPUs is 95, meaning it outperforms 95% of all tested CPUs. Its nearest rivals include the Intel Core Ultra 9 285HX (avgScore 76155, deltaPct 0.1), AMD EPYC Embedded 8224P (avgScore 76492, deltaPct -0.4), AMD Ryzen Threadripper PRO 9945WX (avgScore 76513, deltaPct -0.4), and AMD Ryzen 9 9950X3D (avgScore 75779, deltaPct 0.6). The deltaPct values are tiny (0.1 to -0.4), meaning these CPUs are effectively performance twins. This is remarkable because the 8945HX is a mobile chip competing with desktop and server parts.

In Rust, the CPU's role is substantial. The game's server-side simulation, including entity updates, building stability checks, and environmental events, can scale across multiple threads. The 16 cores and 32 threads provide ample parallelism. However, the measured FPS data suggests that even with this powerful CPU, the system is GPU-limited in most scenarios. At 1080p Low, the 68 FPS average is likely close to the CPU's limit for frame pacing in Rust's engine, but the GPU is still the primary constraint. At 4K, the CPU is clearly not the bottleneck — the FPS drops are entirely attributable to the GPU's inability to render more pixels.

The single-core performance is also relevant. Rust's main game thread handles player input, physics, and AI logic, which are often single-threaded. The 6030 Cinebench R23 single-core score indicates excellent per-core performance, which should keep the main thread from becoming a bottleneck. The 5.40 GHz boost clock is among the highest for mobile CPUs, and this helps maintain smooth frame delivery even when the GPU is struggling. The data implies that in Rust, the 8945HX provides more than enough CPU headroom, and the system's overall performance ceiling is determined by the 890M's graphics capabilities.

How This Combo Ranks — use comboRankInGame vs other tested combos

The combination of the AMD Ryzen 9 8945HX and AMD Radeon 890M ranks 2783 out of 2953 tested combos in Rust, placing it in the bottom 6% of all configurations. This ranking is striking because the CPU alone is in the 95th percentile of all processors, but the GPU is only in the 45th percentile of all GPUs. The combo ranking reflects the reality that Rust's FPS is heavily dependent on GPU performance, and the 890M's integrated nature drags the overall score down despite the CPU's strength.

This rank disparity highlights a fundamental imbalance. The CPU is a top-tier mobile processor capable of handling any game's simulation demands, but the GPU is an integrated solution that competes with decade-old discrete cards. The deltaPct between the 890M and its nearest GPU rivals (Vega 8, GTX 960, GTX 465, GTX 850M) ranges from -0.1 to -1, meaning the 890M is essentially performance-equivalent to those older parts. None of those rivals would be considered adequate for modern gaming at high resolutions, which aligns with the measured FPS data.

The combo's rank of 2783 means that 170 combos perform worse. Those lower-ranked combos likely feature even weaker GPUs or CPUs. But the fact that this combo sits so low despite having a 95th-percentile CPU suggests that in Rust, GPU performance is the dominant factor in determining the overall experience. The measured FPS data supports this: at 1080p Low, the 68 FPS is playable, but at 4K Ultra, the 12 FPS is nearly unusable. The rank reflects the average across all tested resolutions and settings, and the 4K results pull the average down significantly.

Comparing to the CPU's nearest rivals, the 8945HX is virtually tied with the Intel Core Ultra 9 285HX (deltaPct 0.1), AMD EPYC Embedded 8224P (deltaPct -0.4), AMD Ryzen Threadripper PRO 9945WX (deltaPct -0.4), and AMD Ryzen 9 9950X3D (deltaPct 0.6). If any of those CPUs were paired with a stronger discrete GPU, the combo rank would likely be much higher. The data suggests that the 8945HX is wasted in this configuration for Rust, as the CPU's potential is underutilized when the GPU becomes the limiting factor.

Settings Recommendations — which preset gives the best experience per the measured rows

Based on the measured FPS data, the optimal settings for Rust with this combo depend on the target resolution and the user's tolerance for frame rate dips. At 1920x1080, the Low preset yields an average of 68 FPS, which is the only preset that approaches the 60 FPS threshold commonly considered smooth for competitive play. The Medium preset at 1080p averages 46 FPS with a min of 39, which is playable but with noticeable stutters in busy scenes. The High preset at 1080p averages 38 FPS, and Ultra averages 29 FPS. For 1080p, Low is the clear recommendation — the 22 FPS gain over Medium is substantial, and Rust's visual differences between Low and Medium are not critical for gameplay clarity.

At 2560x1440, all presets fall below 50 FPS. The Low preset averages 47 FPS, which is borderline playable but not ideal. Medium averages 31 FPS, High averages 26 FPS, and Ultra averages 20 FPS. The min FPS for Medium is 27, which can cause frustrating hitches during firefights or when loading new areas. Given that the delta between Low and Medium at 1440p is 16 FPS, and the visual quality improvement from Low to Medium is modest, Low is the only viable choice at this resolution for anything resembling smooth gameplay.

At 3840x2160, no preset is truly playable. The Low preset averages 28 FPS, which is below the 30 FPS minimum for most gamers. Medium averages 19 FPS, High averages 16 FPS, and Ultra averages 12 FPS. The min FPS for Medium is 16, which is a slideshow. At 4K, the recommendation would be to avoid this resolution entirely, as even the lowest settings fail to provide an acceptable experience. If forced to choose, Low at 28 FPS is the least bad option, but users should expect significant performance issues.

The data suggests that this combo is best served at 1080p with Low settings for a playable experience. If the user prioritizes visual fidelity over frame rate, Medium at 1080p (46 FPS) is the maximum acceptable setting. For those who must play at 1440p, Low is the only option, and even then, the experience will be suboptimal. The Ultra preset is not recommended at any resolution, as the FPS drops below 30 even at 1080p.

FAQ

Q: What is the best resolution and settings combination for this system in Rust?

A: The measured data shows that 1920x1080 with Low settings yields 68 FPS, which is the highest average across all tested configurations. This is the only combination that exceeds 60 FPS. At 1440p, Low produces 47 FPS, and at 4K, even Low drops to 28 FPS.

Q: Can this system run Rust at 4K?

A: The data indicates that 4K is not viable. The best 4K result is Low settings at 28 FPS, which is below acceptable playability. Medium, High, and Ultra at 4K produce 19, 16, and 12 FPS respectively, making the game effectively unplayable at that resolution.

Q: How does the AMD Radeon 890M compare to its nearest GPU rivals?

A: The 890M scores an average benchmark of 9210, which is nearly identical to the AMD Radeon Vega 8 (9221, deltaPct -0.1), NVIDIA GeForce GTX 960 (9273, deltaPct -0.7), NVIDIA GeForce GTX 465 (9294, deltaPct -0.9), and NVIDIA GeForce GTX 850M (9302, deltaPct -1). All deltaPct values are negative, meaning the 890M is slightly slower than each of these rivals.

Q: Is the CPU or GPU the bottleneck in this system for Rust?

A: The CPU is a top-tier 16-core part with a 95th percentile ranking, while the GPU is an integrated solution at the 45th percentile. The FPS scaling from 1080p to 4K shows a 59% drop on Low settings, which indicates the GPU is the limiting factor at higher resolutions. At 1080p Low, the CPU is likely still not the main constraint.

Q: What is the combo's overall ranking in Rust?

A: This combo ranks 2783 out of 2953 tested combinations, placing it in the bottom 6% of all configurations. This low ranking is due to the integrated GPU's limitations, despite the CPU's strong performance.

Q: What are the minimum FPS values for Medium settings at each resolution?

A: At 1920x1080 Medium, the min FPS is 39. At 2560x1440 Medium, the min FPS is 27. At 3840x2160 Medium, the min FPS is 16. These values indicate that even the Medium preset suffers from occasional frame drops at all resolutions.

Measured FPS Breakdown — resolution by resolution, settings by settings, exact numbers

1920x1080 (1080p):

• Low: 68 FPS average
• Medium: 46 FPS average (min 39, max 52)
• High: 38 FPS average
• Ultra: 29 FPS average

2560x1440 (1440p):

• Low: 47 FPS average
• Medium: 31 FPS average (min 27, max 36)
• High: 26 FPS average
• Ultra: 20 FPS average

3840x2160 (4K):

• Low: 28 FPS average
• Medium: 19 FPS average (min 16, max 21)
• High: 16 FPS average
• Ultra: 12 FPS average

The data shows a consistent pattern: each resolution step down (from 1080p to 1440p to 4K) roughly halves the frame rate for a given settings preset. For Low, the progression is 68 → 47 → 28 FPS. For Medium, it is 46 → 31 → 19 FPS. For High, it is 38 → 26 → 16 FPS. For Ultra, it is 29 → 20 → 12 FPS. This geometric decline indicates that the GPU's pixel throughput is the dominant factor, as the relative FPS loss between resolutions is similar across all settings presets. The min FPS values for Medium (39, 27, 16) show that the floor also scales proportionally, meaning even the worst-case scenarios become progressively worse at higher resolutions.