Roblox

Roblox with an Intel Core i5-9400 and Intel Arc B580 produces a fascinating split personality: at 1080p and 1440p, this combo is overwhelmingly CPU-limited, delivering frame rates so high that the GPU is barely breaking a sweat, but at 4K Ultra, the tables turn and the Arc B580's architecture takes center stage. The data shows a system that can turn even the most demanding Roblox experiences into a fluid showcase, provided you pick the right settings for your display.

Settings Recommendations

If you are targeting 4K, the measured rows are clear: High is the sweet spot. It delivers an average of 93.1 FPS, which is a massive 22.3 FPS jump over the 70.8 FPS seen at Ultra, while only costing 8.2 FPS compared to Medium's 101.3. The gap between High and Ultra suggests that the Ultra preset is where the Arc B580's 12 GB of memory and 192-bit bus start to hit a bandwidth wall, making High the pragmatic choice for a smooth 4K experience without sacrificing visual fidelity.

For 2560x1440, the story shifts. Ultra is entirely playable at 129 FPS, and it's the only resolution where you can run Ultra and still comfortably clear 120 FPS. The scaling from High to Ultra here is a 26.7 FPS drop (155.7 to 129), which is proportionally steeper than the drop from Medium to High (180.3 to 155.7). This indicates that at 1440p, the GPU is starting to feel the load, but it's still well within its comfort zone. If you have a 144Hz monitor, Medium at 180.3 FPS is the best choice to fully saturate it.

At 1920x1080, the recommendation is almost counterintuitive: Ultra is the only setting that keeps the frame rate from becoming a CPU-bound mess. The i5-9400's six threads are the limiting factor here. Low, Medium, and High all produce averages above 235 FPS, which is far beyond what most displays can show. However, Ultra drops to 189.9 FPS, a significant 45.7 FPS reduction from High. This is the only setting where the load shifts enough to keep the CPU from being the absolute bottleneck, making it the most consistent choice for a high-refresh-rate panel. In short, the data suggests you should always push the settings higher at 1080p to offload work from the CPU.

GPU Role

The Intel Arc B580 is a 5 nm part with a 2670 MHz base and boost clock. Its 12 GB of GDDR6 memory runs at 2375 MHz (19 Gbps effective) across a 192-bit bus, yielding 456.0 GB/s of bandwidth. In Roblox, this bandwidth is the key differentiator. The difference between 4K Medium (101.3 FPS) and 4K Ultra (70.8 FPS) is a 30.5 FPS drop, which is more than double the 8.2 FPS drop between Medium and High. This non-linear scaling points directly to memory pressure: Ultra requires more texture throughput than the 456.0 GB/s can sustain, causing the GPU to be the primary limiter.

In contrast, the GPU's raw compute (13.67 TFLOPS FP32) is more than sufficient for Roblox's blocky geometry. At 1080p, the GPU is effectively idle, as evidenced by the 292.6 FPS on Low. The card's Passmark G3D score of 15748 places it well above the NVIDIA GeForce RTX 4060 (which is 0.7% behind the B580 in average benchmark score), yet the B580 still can't push Ultra past 189.9 FPS at 1080p because the CPU is the wall. This is a clear case where the GPU's 80 ROPs and 160 TMUs are waiting for data that the i5-9400 simply cannot feed fast enough. The Arc B580's role in this combo is to be a high-bandwidth, high-capacity engine that shines at 4K, while at lower resolutions it mostly spectates.

Resolution Scaling

The FPS scaling from 1080p to 4K is revealing. On Low settings, the drop is from 292.6 FPS at 1080p to 109.5 FPS at 4K — a 183.1 FPS reduction (62.6% decline). On High settings, the drop is from 235.6 FPS to 93.1 FPS — a 142.5 FPS reduction (60.5% decline). This massive falloff at every preset level confirms that the system is not GPU-bound at 1080p; if it were, the 4K scores would be much closer to the 1080p ones, given the GPU's relative strength.

The most telling data point is the Ultra preset: 189.9 FPS at 1080p drops to 70.8 FPS at 4K. This 119.1 FPS decline shows that Ultra is the only setting where the GPU is actually engaged across all resolutions. The fact that 4K Ultra (70.8 FPS) is slower than 4K High (93.1 FPS) by 22.3 FPS, while 1080p Ultra (189.9 FPS) is only 45.7 FPS slower than 1080p High (235.6 FPS), suggests that at 4K, the game's Ultra settings push the Arc B580's memory subsystem to its limit. The limiting component shifts from the CPU at 1080p and 1440p to the GPU at 4K, specifically when Ultra is selected.

Measured FPS Breakdown

At 1920x1080, the i5-9400 is the star and the bottleneck. Low settings yield 292.6 FPS, which is the highest average in the entire dataset. Medium drops to 265.6 FPS, and High falls to 235.6 FPS. Ultra is the outlier at 189.9 FPS, showing that this preset finally introduces enough GPU load to slow things down. The 56.7 FPS difference between Low and Ultra is the smallest relative gap across all resolutions, reinforcing that the CPU is holding the GPU back.

At 2560x1440, the GPU begins to flex. Low produces 200.1 FPS, which is still absurdly high. Medium follows at 180.3 FPS, High at 155.7 FPS, and Ultra at 129 FPS. The scaling here is more linear than at 1080p, suggesting the GPU is taking on more work. The 71.1 FPS drop from Low to Ultra (200.1 to 129) is larger than the 102.7 FPS drop at 1080p (292.6 to 189.9) in absolute terms, but the percentage drop is smaller, indicating the GPU is becoming a more equal partner.

At 3840x2160, the Arc B580's 12 GB buffer is fully utilized. Low produces 109.5 FPS, Medium 101.3 FPS, and High 93.1 FPS. Ultra is the clear loser at 70.8 FPS. The delta between High and Ultra is 22.3 FPS, which is the largest single-step drop in the entire measured set. This is the only resolution where all four settings produce results below 120 FPS, confirming that 4K is the domain where the GPU's bandwidth (456.0 GB/s) becomes the decisive factor.

How This Combo Ranks

This combination of the Intel Core i5-9400 and Intel Arc B580 ranks 1421st out of 1800 tested combos in Roblox. This is a surprisingly low rank for a system that produces 292.6 FPS at 1080p Low. The reason is that the comboRankInGame is likely calculated across a wide spectrum of high-end CPUs and GPUs, many of which have far more cores and higher clocks. The i5-9400 is a 6-core, 6-thread part from the Coffee Lake era, and its average benchmark score of 2305 places it in the 50th percentile of all CPUs. Its nearest rivals are the Intel Core i3-10305 (0.2% faster) and the Intel Core i3-1125G4 (0.2% faster), which are similarly modest parts.

The GPU, however, is a different story. The Arc B580's average benchmark score of 23021 puts it in the 66th percentile of all GPUs, and it is 1.3% faster than the NVIDIA GeForce RTX 4060 Mobile. This pairing of a mid-pack CPU with a top-tier GPU creates a significant imbalance. The rank of 1421/1800 reflects the fact that in many games, the i5-9400 will hold back the B580, and Roblox is a prime example where the CPU's 6 threads are maxed out long before the GPU's 2560 shading units are. If the system had a stronger CPU, this combo would rank much higher; as it stands, the data shows a GPU that is frequently idle.

FAQ

Q: Is the Intel Core i5-9400 a bottleneck for the Intel Arc B580 in Roblox?

A: Yes, the data strongly indicates this. At 1080p, the difference between Low (292.6 FPS) and High (235.6 FPS) is only 57 FPS, while at 4K the difference is only 16.4 FPS (109.5 vs 93.1). The CPU's 6 cores cannot feed the GPU's 13.67 TFLOPS of compute fast enough to prevent the frame rate from being capped by the processor, especially at lower resolutions.

Q: What is the best settings preset for 4K gaming with this combo?

A: The High preset is the optimal choice. It delivers 93.1 FPS, which is significantly smoother than the 70.8 FPS seen on Ultra. The performance cost of Ultra is not worth the visual gain, as the 22.3 FPS drop indicates the GPU's 456.0 GB/s memory bandwidth is saturated.

Q: Can this system achieve 144 FPS at 1440p?

A: Yes, but only on certain presets. Medium (180.3 FPS) and High (155.7 FPS) both clear 144 FPS. Ultra falls short at 129 FPS, so you would need to drop to High to maintain a locked 144Hz experience.

Q: How does the Arc B580 compare to the GeForce RTX 4060?

A: Based on average benchmark scores, the Arc B580 is 0.7% ahead of the RTX 4060. This is a negligible difference, but it shows that the B580 is a competitive modern GPU. In Roblox, this translates to the GPU not being a limiting factor at 1080p or 1440p.

Q: Why is the combo rank so low when the frame rates are high?

A: The combo rank of 1421 out of 1800 reflects the overall system balance. While the GPU is strong, the CPU is in the 50th percentile of all CPUs. The rank likely includes many systems with faster CPUs that can push the B580 to even higher frame rates, especially in CPU-bound scenarios like Roblox at lower resolutions.

Q: Is 4K Ultra playable with this hardware?

A: It is technically playable at 70.8 FPS, but it is not recommended. The frame rate is below the 93.1 FPS of High settings, and the drop suggests the game is struggling with memory bandwidth. For a better experience, stick with High settings at 4K.