Roblox

Roblox with the Intel Core i5-9400 and NVIDIA GeForce RTX 3080 exhibits a profound shift in bottleneck behavior as resolution changes. At 1080p, the combination produces exceptionally high frame rates, with the average FPS ranging from 312.7 at Ultra settings to 485.1 at Low settings. The gap between Low and Ultra at 1080p is substantial, indicating that while the GPU is capable of immense throughput, the CPU is likely the limiting factor at these lower resolutions. As the resolution increases to 1440p, the average FPS drops across all settings, with the Low setting still achieving 321.9 FPS and Ultra settling at 211.6 FPS. The scaling from 1080p to 1440p shows a reduction of approximately 17% for Low settings and about 32% for Ultra, suggesting that the load is beginning to shift more toward the GPU.

Moving to 4K (3840x2160), the performance curve becomes more pronounced. The average FPS at High settings is 146.9, while Medium achieves 166 FPS, Low hits 179.4 FPS, and Ultra drops to 118.1 FPS. The transition from 1440p to 4K represents a significant performance hit, with High settings falling from 255.6 FPS to 146.9 FPS, a reduction of roughly 43%. This steep decline indicates that at 4K, the RTX 3080 is becoming the primary bottleneck, as its raw compute and memory bandwidth are taxed by the higher pixel count. The data shows that the 1080p results are heavily CPU-limited, evidenced by the relatively small FPS delta between Low and Medium settings (485.1 vs 436.6) compared to the larger delta between Medium and Ultra (436.6 vs 312.7). At 4K, the GPU’s limitations are clear: the difference between Low and Ultra is 61.3 FPS, which is a smaller absolute gap than at 1080p (172.4 FPS), but the overall frame rates are far lower, underscoring the GPU's dominance in determining performance at this resolution.

FAQ

Q: What is the highest average FPS recorded for this combo, and at what settings?

A: The highest average FPS is 485.1, achieved at 1920x1080 resolution with Low settings. This is followed by 436.6 FPS at Medium settings and 389.5 FPS at High settings for the same resolution.

Q: How does the RTX 3080's benchmark score compare to its closest rivals?

A: The RTX 3080 has an average benchmark score of 35787. Its nearest rival, the AMD Radeon Pro Duo, scores 35860, which is 0.2% higher. The AMD Radeon 880M scores 35646, which is 0.4% lower. The AMD Radeon RX 7900 GRE scores 36101, which is 0.9% higher, and the NVIDIA GeForce RTX 5070 Ti Mobile scores 35435, which is 1% lower.

Q: What is the performance difference between the i5-9400 and its nearest rival in synthetic benchmarks?

A: The Intel Core i5-9400 has an average benchmark score of 2305. Its nearest rival, the Intel Core i3-10305, scores 2300, which is 0.2% lower. The Intel Core i3-1125G4 also scores 2299, 0.2% lower, while the Intel Xeon E-2134 scores 2295, 0.4% lower. The Intel Core i7-8809G scores 2319, which is 0.6% higher than the i5-9400.

Q: Does the CPU or GPU limit performance more at 4K resolution?

A: At 4K, the GPU is the primary limiting component. The average FPS across all settings (118.1 to 179.4) is significantly lower than at 1080p, and the scaling between settings is compressed, indicating that the RTX 3080's processing capacity is the main constraint rather than the i5-9400.

Q: What is the combo's ranking among all tested combinations for Roblox?

A: The combo ranks 558th out of 1800 tested combinations in Roblox. This places it in the top third of all tested combos, though the high FPS numbers suggest that the ranking may be influenced by other factors such as consistency or specific benchmark conditions.

Q: How much faster is the Low setting compared to Ultra at 1440p?

A: At 2560x1440, the Low setting achieves an average FPS of 321.9, while the Ultra setting achieves 211.6. This means the Low setting is approximately 52% faster than Ultra at this resolution, a significant margin that highlights the impact of graphical fidelity on frame rates.

How This Combo Ranks

The Intel Core i5-9400 and NVIDIA GeForce RTX 3080 combination ranks 558th out of 1800 tested combos in Roblox. This position, while not at the top, is respectable given the specific pairing's characteristics. The i5-9400 is a 6-core, 6-thread processor from the Coffee Lake architecture, with a base clock of 2.90 GHz and a boost clock of 4.10 GHz. Its synthetic benchmark average is 2305, placing it at the 50th percentile among all CPUs tested. The RTX 3080, on the other hand, is a high-end Ampere architecture GPU with an average benchmark score of 35787, placing it at the 80th percentile among all GPUs. The ranking of 558 suggests that while the GPU is exceptionally powerful, the CPU's mid-range standing (50th percentile) may be holding back the combination in certain scenarios, particularly at lower resolutions where CPU overhead is more significant.

The data indicates that the combo's ranking is a result of the balance between these two components. In Roblox, a game that is not particularly demanding on modern hardware, the RTX 3080's raw power (29.77 TFLOPS FP32) is more than sufficient, but the i5-9400's older architecture and lack of hyper-threading (6 cores, 6 threads) could limit performance in CPU-bound situations. The nearest CPU rivals, such as the Intel Core i3-10305 (0.2% lower score) and the Intel Core i7-8809G (0.6% higher score), show that the i5-9400 sits in a tight performance band, making it a balanced but not exceptional choice for this GPU. The ranking of 558 out of 1800 puts it in the 69th percentile of all combos, which is above average but not in the top tier, likely due to the CPU's inability to fully feed the RTX 3080 at lower resolutions.

Measured FPS Breakdown

At 1920x1080, the average FPS values are as follows: Low settings produce 485.1 FPS, Medium settings produce 436.6 FPS, High settings produce 389.5 FPS, and Ultra settings produce 312.7 FPS. The spread between Low and Ultra is 172.4 FPS, with the most significant single-step drop occurring between Medium and High (47.1 FPS) and between High and Ultra (76.8 FPS). This pattern suggests that the CPU is the limiting factor at 1080p, as the GPU has ample headroom to render frames quickly, but the i5-9400's 6-core, 6-thread configuration cannot keep up with the demand for high frame rates, especially at higher settings that may introduce additional draw calls or physics calculations.

At 2560x1440, the average FPS values are: Low at 321.9 FPS, Medium at 295.1 FPS, High at 255.6 FPS, and Ultra at 211.6 FPS. The difference between Low and Ultra is 110.3 FPS, which is narrower than at 1080p. The step from High to Ultra is 44 FPS, while the step from Medium to High is 39.5 FPS. The overall reduction from 1080p to 1440p is approximately 17% for Low, 15% for Medium, 13% for High, and 12% for Ultra. This smaller percentage drop at higher settings indicates that the GPU is starting to become more involved in the rendering pipeline, but the CPU still exerts a noticeable influence.

At 3840x2160, the average FPS values are: Low at 179.4 FPS, Medium at 166 FPS, High at 146.9 FPS, and Ultra at 118.1 FPS. The spread between Low and Ultra is 61.3 FPS, which is the smallest absolute spread across all resolutions. The percentage drop from 1440p to 4K is significant: Low falls by 44%, Medium by 44%, High by 43%, and Ultra by 44%. This uniform reduction across settings is a clear indicator that the RTX 3080 is now the primary bottleneck, as its memory bandwidth of 760.3 GB/s and 10 GB of GDDR6X memory are being fully utilized to push the higher pixel count. The data shows a clear progression: CPU-limited at 1080p, a balanced load at 1440p, and GPU-limited at 4K.

CPU Role

The Intel Core i5-9400 features 6 cores and 6 threads, with a base clock of 2.90 GHz and a boost clock of 4.10 GHz. It is built on the Coffee Lake architecture using a 14 nm process node, and it has a 9 MB shared L3 cache. Its synthetic benchmark scores are modest: a Cinebench R23 multi-core score of 7969 and a single-core score of 1125. The CPU's average benchmark score is 2305, placing it at the 50th percentile of all CPUs, with nearest rivals including the Intel Core i3-10305 (0.2% higher) and the Intel Core i7-8809G (0.6% lower). In the context of Roblox, the CPU's role is critical at lower resolutions. The data shows that at 1080p, the FPS is extremely high, but the scaling from Low to Ultra is not linear, suggesting that the CPU's 6 threads are being saturated by the game's logic and rendering commands. The lack of hyper-threading means that the CPU can only handle 6 concurrent threads, which can become a bottleneck in scenarios with many active objects or scripts, which are common in Roblox's sandbox gameplay.

At higher resolutions, the CPU's influence wanes. The shift in bottleneck from CPU to GPU is evident in the FPS data: at 4K, the FPS values are much lower and the relative differences between settings are smaller, indicating that the RTX 3080's 8704 shading units and 68 RT cores are the limiting factor. The CPU's boost clock of 4.10 GHz is sufficient to maintain high single-thread performance, but the overall architecture is dated compared to newer processors. The benchmark data shows that the i5-9400 is a mid-range CPU, performing similarly to its rivals within a 0.6% margin, which reinforces the idea that it is not a top-tier part. In Roblox, this translates to a system that can deliver excellent frame rates, but the CPU's limitations are exposed when trying to maximize FPS at 1080p, where the RTX 3080 is capable of far more than the CPU can feed it. The measured FPS at 1080p Low (485.1) versus 4K Low (179.4) highlights this dynamic, showing that the CPU allows for high performance but cannot sustain it as the GPU's workload increases.