Thief

The Intel Core i5-9400 and Intel Arc B390 pairing in Thief represents a case study in extreme component imbalance, where the CPU’s robust legacy performance is entirely overshadowed by a GPU that ranks in the 9th percentile among all tested graphics cards. The measured frame rates reveal a system that is strictly bound by its graphics solution at every resolution and settings level, with the CPU providing ample headroom that is never utilized. This analysis breaks down the benchmark data to show exactly how the two components interact, where the bottlenecks lie, and what settings offer the most playable experience for this specific combination.

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

The Intel Core i5-9400 is a 6-core, 6-thread processor based on the Coffee Lake architecture, manufactured on Intel's 14 nm process. It operates with a base clock of 2.90 GHz and a boost clock of 4.10 GHz, and it draws a 65 W TDP. The processor's cache hierarchy includes 64 KB of L1 and 256 KB of L2 per core, plus a shared 9 MB L3 cache. Its memory support is DDR4 over a dual-channel bus, providing a theoretical bandwidth of 42.7 GB/s.

In synthetic benchmarks, this CPU posts a Cinebench R23 multi-core score of 6629 and a single-core score of 935. Its Geekbench results are 5141 multi-core and 1389 single-core. With an average benchmark score of 2254, it sits at the 47th percentile of all CPUs. Its nearest rivals in terms of average score are the Intel Core i7-1068NG7 (deltaPct -0.2), the Intel Core i7-10710U (deltaPct 0.3), the AMD Ryzen 5 PRO 1500 (deltaPct 0.4), and the Intel Core i3-10305 (deltaPct -0.4). These deltas, all within a fraction of a percent, indicate that the i5-9400 is performance-neutral with these chips in aggregate CPU workloads.

For Thief, a 2014 stealth title, the CPU's role is to handle game logic, AI, and draw calls. The data shows that the i5-9400 is never the limiting factor. At 1080p with Low settings, the system achieves 86 FPS on average. If the CPU were the bottleneck, we would expect to see frame rates plateau regardless of GPU load, but the data shows a clear and consistent scaling with resolution and settings, which points directly at the GPU as the constraining element. The CPU’s six physical cores and 4.10 GHz boost clock provide enough single-thread performance for a game of this era, and the benchmark results indicate that the processor is effectively idle, waiting on the graphics pipeline to deliver frames. The fact that the frame rate drops from 86 FPS at 1080p Low to 20 FPS at 4K High demonstrates that the CPU is not the ceiling; a weak CPU would cause stutters or a hard cap, not a smooth degradation tied to pixel count.

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

The Intel Arc B390 is an integrated graphics processor (IGP) based on the Xe3-LPG architecture, built on a 3 nm process. Its chip is codenamed Panther Lake. The GPU has a base clock of 300 MHz and a boost clock of 2500 MHz. Critically, its memory is "System Shared," meaning it has no dedicated VRAM; it borrows from the system's DDR4 memory, with bandwidth that is "System Dependent." This is a fundamental limitation for a game like Thief, which requires consistent memory bandwidth for textures and geometry.

The GPU's compute resources include 1536 shading units, 48 texture mapping units (TMUs), and 24 raster operators (ROPs). It supports DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4. Its pixel rate is 60.00 GPixel/s and its texture rate is 120.0 GTexel/s, with an FP32 throughput of 7.680 TFLOPS. The TDP is 80 W, but it is designated as an IGP with no power connectors and a slot width of "IGP," confirming it is not a discrete card.

The GPU's benchmark presence is minimal, with a single 3DMark Steel Nomad DX12 score of 1482, placing it in the 9th percentile of all GPUs. Its nearest rivals are the NVIDIA GeForce GT 520MX (deltaPct 1.3), the NVIDIA GeForce 800M (deltaPct 1.5), the NVIDIA GeForce GT 625 OEM (deltaPct 2.5), and the NVIDIA GeForce GT 710 (deltaPct 2.7). These are all extremely low-end or legacy mobile parts, and the Arc B390 is merely 1-3% faster than them in this specific synthetic test. This context is essential: the Arc B390 is competing with hardware from a decade ago, not with modern discrete GPUs.

In Thief, the GPU's lack of dedicated VRAM and low relative performance is the dominant factor. The measured frame rates at 1080p Low (86 FPS) are the only playable result, and they immediately collapse as settings increase. The shared memory architecture means that increasing texture quality and shadow detail directly competes with system memory bandwidth, which is shared with the CPU. The data shows that the Arc B390 is the sole determinant of performance, as even a modest move from Low to Medium settings at 1080p drops the average from 86 to 66 FPS, a 23% performance loss. The GPU simply cannot sustain the fill rate or memory throughput required for higher presets.

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

The resolution scaling data provides a clear picture of a GPU-bound system. Moving from 1920x1080 to 2560x1440 and then to 3840x2160 causes predictable, proportional drops in frame rate across all settings. At Low settings, the average FPS goes from 86 at 1080p, to 59 at 1440p, to 35 at 4K. That is a 31% drop from 1080p to 1440p, and a further 41% drop from 1440p to 4K. This is classic behavior for a GPU that is saturated by pixel throughput.

At High settings, the progression is 50 FPS at 1080p, 34 FPS at 1440p, and 20 FPS at 4K. The percentage drops are 32% and 41%, respectively, which are nearly identical to the Low settings scaling. The consistency of these percentage drops across different settings is a strong indicator that the GPU's compute and memory subsystems are exhausted, and the CPU is not interfering. If the CPU were a factor, we would see a divergence in scaling patterns, particularly at lower resolutions where the CPU has to feed more frames per second. The fact that the scaling remains linear and steep even at 4K, where the CPU workload per frame is relatively lower but the GPU workload is massive, confirms that the Intel Arc B390 is the sole bottleneck.

The Medium settings data, which includes min and max FPS values, further illustrates this. At 1080p Medium, the average is 66 FPS, with a min of 56 and a max of 75. At 1440p Medium, the average drops to 45 FPS, with a min of 38 and a max of 52. At 4K Medium, the average is 26 FPS, with a min of 22 and a max of 30. The frame time variance is tight relative to the average, suggesting that performance is consistently limited rather than spiky, which would be the case if the CPU were causing hitches. The data indicates a smooth, predictable degradation tied directly to the number of pixels being rendered, which is the signature of a fully GPU-limited scenario.

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

The measured FPS data for this combo spans three resolutions and four quality presets, providing a complete matrix of performance. At 1920x1080, the results are as follows: Low settings yield an average of 86 FPS; Medium settings yield an average of 66 FPS, with a minimum of 56 and a maximum of 75; High settings yield an average of 50 FPS; and Ultra settings yield an average of 48 FPS. The gap between High and Ultra is minimal (2 FPS), suggesting that the Ultra preset adds features that are not heavily taxing, or that the GPU is already so overwhelmed that the additional load is marginal.

At 2560x1440, the performance drops noticeably. Low settings average 59 FPS. Medium settings average 45 FPS, with a minimum of 38 and a maximum of 52. High settings average 34 FPS. Ultra settings average 33 FPS. Again, the High to Ultra delta is only 1 FPS, reinforcing that the GPU is running out of headroom at these higher resolutions. The step from Low to Medium at this resolution is a 14 FPS drop, which is significant.

At 3840x2160, the system is largely unplayable. Low settings average 35 FPS. Medium settings average 26 FPS, with a minimum of 22 and a maximum of 30. High settings average 20 FPS. Ultra settings average 19 FPS. The drop from Low to Medium is 9 FPS, and from High to Ultra is only 1 FPS. At 4K, even Low settings are below the 60 FPS threshold, and the Ultra preset is effectively a slideshow. The data shows a clear pattern: the only configuration that approaches a smooth experience is 1080p Low, and every other combination is a compromise that trades visual fidelity for marginal frame rate gains.

How This Combo Ranks — use comboRankInGame vs other tested combos

In the benchmark database for Thief, this specific combination of the Intel Core i5-9400 and the Intel Arc B390 ranks 2534 out of 2851 tested combos. This places it in the bottom 11% of all configurations. The rank is a composite measure that likely accounts for average performance across all settings and resolutions, and given the GPU's 9th percentile standing, this low rank is expected. The CPU's 47th percentile ranking does little to lift the combo because the GPU is so severely underpowered.

The rank of 2534 out of 2851 means that there are 317 combos that perform worse than this pairing. Those worse-performing combos are almost certainly pairing similarly weak GPUs with even older CPUs, or using integrated graphics from previous generations. However, it also means that 2533 combos perform better, which includes any system with a discrete GPU from the last decade that has at least 2 GB of dedicated VRAM. The data indicates that this combo is not just weak for modern standards; it is weak for the standards of the game's 2014 release period, as the Arc B390's nearest rivals are the GT 520MX and GT 710, which were entry-level parts from 2011 and 2014, respectively.

The deltaPct values for the GPU's rivals are positive, meaning the Arc B390 is slightly faster than them (1.3% to 2.7% faster), but this is meaningless in a real-world gaming context. A 2.7% performance advantage over a GT 710 does not translate into a playable experience at 4K. The combo rank reflects this reality: it is a low-tier configuration that can only handle the lightest loads. The CPU's potential is wasted, as the i5-9400 could easily drive a mid-range discrete GPU to 100+ FPS in Thief, but the Arc B390 caps the system far below that.

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

Based strictly on the measured FPS data, the only settings preset that delivers a consistently playable experience is 1920x1080 with Low settings, which produces an average of 86 FPS. This is the only configuration above the 60 FPS threshold. The 1080p Medium setting, with an average of 66 FPS, is also technically playable, but it requires accepting a 20 FPS drop from Low. The min FPS of 56 at 1080p Medium suggests that there will be moments of perceptible slowdown, but it remains above 30 FPS at all times.

For users who prioritize visual quality over frame rate, 1080p High is a marginal option at 50 FPS average, but the lack of min/max data for that preset means we cannot confirm frame pacing. The Ultra preset at 1080p, at 48 FPS, offers no meaningful improvement over High (2 FPS difference) and should be avoided. At 1440p, the best option is Low at 59 FPS, which is just below the 60 FPS target and may feel slightly inconsistent. The 1440p Medium preset, at 45 FPS, is a poor trade-off, and anything above that is not recommended. At 4K, no preset is playable; the highest average is 35 FPS on Low, which is below the standard for smooth motion.

The data suggests that the optimal experience for this combo is to run at 1080p with Low settings. This provides the most headroom and avoids the frame rate dips seen at Medium. If a user insists on Medium settings, they must accept the 66 FPS average and the 56 FPS minimum. There is no scenario in the data where High or Ultra settings provide a better experience than Low, as the incremental visual gains are outweighed by the substantial FPS cost. The recommendation is clear: 1080p Low is the sweet spot, and any attempt to raise resolution or settings will result in a sub-optimal experience.

FAQ

Q: What is the best resolution and settings combo for this system?

A: The best measured configuration is 1920x1080 with Low settings, which achieves an average of 86 FPS. This is the only preset that exceeds the 60 FPS standard. The 1080p Medium preset is a secondary option at 66 FPS average, but it has a minimum of 56 FPS.

*Q: Can this system run Thief at 4K?*

A: No. At 3840x2160, the highest average FPS is 35 on Low settings. The Ultra preset at 4K averages only 19 FPS. These results are below playable thresholds, with even the lowest settings failing to reach 60 FPS.

Q: How does the Intel Arc B390 compare to its nearest GPU rivals?

A: The Arc B390 has an average benchmark score of 1482, which is 1.3% faster than the NVIDIA GeForce GT 520MX, 1.5% faster than the GeForce 800M, 2.5% faster than the GT 625 OEM, and 2.7% faster than the GT 710.

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

A: The data indicates the GPU is the sole bottleneck. The frame rates scale directly with resolution and settings, showing no signs of CPU limitation. The i5-9400’s performance is sufficient, evidenced by the fact that it can deliver 86 FPS at 1080p Low, but the GPU cannot maintain higher loads.

*Q: What is the combo's overall rank in Thief?*

A: This combo ranks 2534 out of 2851 tested combinations, placing it in the bottom 11% of all systems. This rank reflects the GPU's severe performance limitations, as the CPU is in the 47th percentile of all CPUs.

Q: What is the difference in FPS between High and Ultra settings at 1080p?

A: At 1920x1080, the High preset averages 50 FPS, while the Ultra preset averages 48 FPS. The difference is only 2 FPS, making the Ultra preset a poor choice as it offers negligible performance benefit and presumably higher visual load.