Rust

Rust is a notoriously CPU-intensive survival game, and pairing the 12-core Intel Core i7-12700KF with the integrated Intel Arc B390 graphics creates a striking bottleneck dynamic. The measured frames per second (FPS) data reveals a system where the discrete-class iGPU is the overwhelming limiting factor, yet the high-core-count CPU ensures that frame pacing remains stable even when the renderer is saturated. This analysis breaks down the measured results, contextualizes them against rival hardware, and provides actionable settings guidance based strictly on the provided data.

Resolution Scaling

The FPS drop from 1080p to 4K is severe and tells a clear story about which component is the bottleneck. At 1080p with Low settings, the combo produces an average of 76 FPS. Moving to 1440p Low drops that to 53 FPS, a 30% reduction. At 4K Low, the average falls to 31 FPS, which is a 59% drop from the 1080p Low figure. This scaling pattern is characteristic of a GPU that is completely overwhelmed by pixel count; the Intel Arc B390’s 1536 shading units and 24 ROPs are simply not enough to maintain throughput as resolution increases.

The High settings preset shows an even more dramatic collapse. At 1080p High, the average is 43 FPS, but this drops to 30 FPS at 1440p (a 30% loss) and then to just 18 FPS at 4K (a 58% loss from 1080p). The consistency of the percentage drops across settings presets—roughly a 30% hit from 1080p to 1440p and another 40% hit from 1440p to 4K—indicates that the rendering pipeline is purely shader-bound. The CPU, with its 20 threads and 5.00 GHz boost clock, is not the constraint here; if it were, we would see less variance between resolution steps.

What makes this data curious is that the i7-12700KF is capable of far higher frame rates in CPU-bound scenarios, as evidenced by its Cinebench R23 multi-core score of 28838. The fact that 4K Ultra yields only 13 FPS—while 1080p Low yields 76 FPS—suggests that the Arc B390 is operating at its absolute limits for fill-rate and pixel shading. The 2500 MHz boost clock on the GPU helps at lower resolutions, but the system-shared memory bandwidth (labeled "System Dependent") becomes a severe liability at 4K, where the memory bus width is also "System Shared." This is not a case of the CPU holding back the GPU; it is the inverse, with the iGPU acting as a hard cap on playability.

FAQ

Q: Why does the 4K Ultra preset produce only 13 FPS when the CPU is so strong?

A: The bottleneck is the Intel Arc B390’s integrated graphics. With only 24 ROPs and a pixel rate of 60.00 GPixel/s, the GPU cannot handle the 8.3 million pixels of 4K resolution under Ultra settings. The CPU’s 12 cores and 20 threads are idle waiting for the GPU to finish each frame, as evidenced by the fact that dropping to Low settings at 4K nearly doubles the frame rate to 31 FPS.

Q: Is there any resolution where this combo is playable?

A: Yes, at 1080p with Low settings, the measured average is 76 FPS, which is generally considered smooth. The 1080p Medium preset yields 51 FPS, which is also playable for most users. However, the 1440p Low preset at 53 FPS is the only viable option at that resolution, as 1440p Medium drops to 35 FPS and 1440p High falls to 30 FPS.

Q: How does the GPU compare to its closest rivals in raw performance?

A: The Arc B390 scores 1482 in 3DMark Steel Nomad DX12. Its nearest rival, the NVIDIA GeForce GT 520MX, scores 1463, which is a deltaPct of 1.3% slower. The Arc B390 is also 1.5% faster than the GeForce 800M and 2.5% faster than the GT 625 OEM. This places the GPU in the 9th percentile of all GPUs, indicating it is a very low-end part.

Q: What does the combo rank tell us about overall performance?

A: The combo ranks 2601 out of 2953 tested combinations in Rust. This places it in the bottom 12% of all combos. Given the CPU’s 85th percentile ranking among all CPUs, this low combo rank is almost entirely attributable to the GPU’s weak performance.

Q: Does the CPU’s memory support affect the GPU’s performance?

A: The CPU supports both DDR4 and DDR5 memory. Since the GPU uses "System Shared" memory, the bandwidth is "System Dependent." Using faster DDR5 memory would likely improve the GPU’s performance, but the data does not specify which memory type was used for these tests. The 25 MB of shared L3 cache on the CPU does help reduce memory latency, but it cannot compensate for the lack of dedicated VRAM bandwidth.

Q: Are the FPS numbers consistent across presets?

A: The data shows some variance. At 1080p Medium, the FPS ranges from a minimum of 44 to a maximum of 59, with an average of 51. At 1440p Medium, the range is 30 to 41, averaging 35. At 4K Medium, the range is 18 to 24, averaging 21. This suggests that while the average is stable, there are occasional dips, likely due to CPU-side simulation spikes in Rust’s world, which the i7-12700KF handles well.

How This Combo Ranks

The comboRankInGame places this specific CPU+GPU pairing at 2601 out of 2953 tested combinations. This is a low rank, but the reasons are illuminating. The CPU alone is in the 85th percentile of all CPUs, with an average benchmark score of 35365. Its nearest rival, the Intel Core i7-13700T, scores 35403, which is only 0.1% higher. This puts the 12700KF in elite company for processing power.

The GPU, however, is in the 9th percentile of all GPUs. Its average benchmark score is 1482, which is barely above the NVIDIA GeForce GT 520MX (1463) and the GeForce 800M (1460). This extreme disparity between the CPU’s high percentile and the GPU’s low percentile explains the combo’s poor ranking. The data indicates that in Rust, the frame rate is almost entirely dictated by the GPU, meaning the 12-core CPU’s potential is left untapped.

What is interesting is that the combo rank of 2601 is not lower. This suggests that even with a weak GPU, the CPU’s high single-thread performance (3dmark_single_thread score of 1043 and Passmark single-thread score of 3984) helps maintain minimum frame rates in CPU-heavy moments. The 1080p Low average of 76 FPS is actually higher than what a less capable CPU might achieve with the same GPU, indicating that the i7-12700KF is doing its part to feed the GPU efficiently. But the overall rank confirms that users should not expect a high-refresh-rate experience at higher resolutions.

Measured FPS Breakdown

At 1920x1080, the data shows a clear hierarchy of presets. Low settings yield an average of 76 FPS. Medium settings average 51 FPS, with a measured minimum of 44 and maximum of 59. High settings average 43 FPS. Ultra settings drop to an average of 33 FPS. The step from Low to Medium is a 33% performance hit, while the step from Medium to High is a 16% hit, and High to Ultra is a 23% hit. This indicates that the Low preset is the most efficient for 1080p gaming.

Moving to 2560x1440, the averages drop significantly. Low settings yield 53 FPS. Medium settings average 35 FPS (min 30, max 41). High settings average 30 FPS. Ultra settings average 23 FPS. The 1440p Low preset is the only one that breaks the 50 FPS threshold, making it the sole playable option for 1440p. The gap between 1440p Low and 1440p Medium is 34%, which is a larger percentage drop than the equivalent 1080p step, suggesting the GPU is struggling more with the higher pixel count.

At 3840x2160, the results are mostly unplayable. Low settings average 31 FPS. Medium settings average 21 FPS (min 18, max 24). High settings average 18 FPS. Ultra settings average 13 FPS. The 4K Low preset is the only one that approaches playability, but even it is below the 35 FPS threshold that most users consider acceptable for a survival game. The data shows a linear degradation from 1080p Low (76 FPS) to 4K Low (31 FPS), confirming that the GPU is the sole limiting factor.

Settings Recommendations

Based strictly on the measured FPS rows, the best experience is achieved at 1080p with the Low preset, which yields an average of 76 FPS. This is the only configuration that approaches high-refresh-rate territory. If a user prefers visual fidelity over frame rate, the 1080p Medium preset at 51 FPS is the next best option, providing a 33% improvement in visual quality for a 33% reduction in FPS. The 1080p High preset at 43 FPS is borderline, but the 1080p Ultra preset at 33 FPS is not recommended due to the risk of drops below 30 FPS.

For users with 1440p monitors, the Low preset at 53 FPS is the only viable choice. The 1440p Medium preset at 35 FPS is playable but will feel less smooth, and the 1440p High preset at 30 FPS is at the edge of playability. The Ultra preset at 23 FPS is not recommended. At 4K, no preset is truly playable, but the Low preset at 31 FPS is the least bad option for screenshot purposes. The data suggests that the Arc B390 is best utilized at 1080p with low graphical demands.

The measured FPS ranges for Medium presets indicate that the game is stable. At 1080p Medium, the min and max are 44 and 59, a narrow band of 15 FPS. At 1440p Medium, the band is 11 FPS (30 to 41). At 4K Medium, the band is 6 FPS (18 to 24). This narrowing range at higher resolutions suggests that the GPU is becoming more consistently saturated, reducing the impact of CPU-side frame time variance. For the smoothest experience, 1080p Low is the clear winner.

CPU Role

The Intel Core i7-12700KF is a 12-core, 20-thread processor based on the Alder Lake architecture, with a base clock of 3.60 GHz and a boost clock of 5.00 GHz. Its benchmark results are exceptional: the Cinebench R23 multi-core score of 28838 and single-core score of 4071 place it in the 85th percentile of all CPUs. In Rust, which is known for being CPU-intensive, this processor should theoretically provide a solid foundation.

However, the measured FPS data shows that the CPU’s power is largely wasted in this configuration. The fact that 4K Ultra produces 13 FPS while 1080p Low produces 76 FPS suggests that the CPU is not the bottleneck at any resolution. The 3dmark_16_threads score of 9282 and the passmark_multithread score of 34092 indicate that the CPU has ample headroom for the game’s simulation threads. The L3 cache of 25 MB (shared) is beneficial for keeping world data close to the cores.

The CPU’s role here is to ensure that the GPU is fed with consistent draw calls. The narrow FPS ranges at Medium settings (e.g., 44-59 at 1080p) suggest that the CPU is preventing stutters. If the CPU were weaker, we would likely see more severe dips below the average. The i7-12700KF’s high single-thread performance (Passmark single-thread score of 3984) is crucial for Rust’s main thread, which handles the game logic. But even with this strong CPU, the GPU’s 7.680 TFLOPS of FP32 performance is insufficient to translate that CPU power into high frame rates at higher resolutions.

GPU Role

The Intel Arc B390 is an integrated GPU based on the Xe3-LPG architecture, built on a 3 nm process. It has 1536 shading units, 48 TMUs, and 24 ROPs, with a boost clock of 2500 MHz. Its raw compute is 7.680 TFLOPS FP32, but its memory is "System Shared," meaning it relies on the CPU’s memory bandwidth, which is "System Dependent." This is the GPU’s Achilles’ heel.

In Rust, the GPU’s role is to render the vast open world, including terrain, buildings, and dynamic lighting. The 3DMark Steel Nomad DX12 score of 1482 places it in the 9th percentile, just ahead of the NVIDIA GeForce GT 520MX (1.3% slower). This low score is reflected in the FPS data: at 1080p Low, the GPU can manage 76 FPS, but at 4K Ultra, it collapses to 13 FPS. The pixel rate of 60.00 GPixel/s and texture rate of 120.0 GTexel/s are simply not enough for 4K.

The lack of dedicated VRAM is a major issue. With "System Shared" memory, the GPU must compete with the CPU for memory bandwidth. The 2500 MHz boost clock helps at lower resolutions, but the memory bus width being "System Shared" means that at 4K, the memory subsystem becomes a severe bottleneck. The data shows that the GPU is the primary limiter across all resolutions and settings. The 12 RT cores are present, but they do not appear to provide any tangible benefit in this game, as the average FPS at 4K High (18 FPS) is still very low. The GPU is simply outclassed for modern gaming at resolutions above 1080p.