Roblox

The Intel Core i5-9400 and AMD Radeon RX 6600 XT combination delivers extremely high frame rates in Roblox, with performance so strong that the experience is defined by the ceiling of the game's engine and the specific preset selected. Across all tested resolutions, the combo never drops below 78.7 frames per second, indicating a platform that is fully capable of saturating high-refresh-rate displays.

Resolution Scaling

The frame rate scaling from 1080p to 4K is unusually linear and steep, which is atypical for a game of Roblox's visual complexity. At 1080p with Low settings, the combo produces 307.5 FPS, which drops to 205.7 FPS at 1440p and 116.4 FPS at 4K. This represents a 33% reduction from 1080p to 1440p, and a further 43% reduction from 1440p to 4K, showing that the GPU is being taxed heavily as pixel count increases. The pattern is consistent across all presets, with the Ultra preset showing the most dramatic scaling: 198.1 FPS at 1080p falls to 134.6 FPS at 1440p and then to 78.7 FPS at 4K. The overall trend indicates that at 1080p and 1440p, the system is partially CPU-bound or engine-limited, as the frame rates exceed what the GPU alone would typically sustain in more demanding titles. However, at 4K, the RX 6600 XT becomes the clear limiting component, with the gap between Low and Ultra settings narrowing to just 37.7 FPS. The 4K results across all settings (78.7 to 116.4 FPS) suggest that the GPU's 8 GB of VRAM and 256.0 GB/s of bandwidth are sufficient for Roblox's textures, but the raw shader throughput is what caps performance at this resolution.

GPU Role

The AMD Radeon RX 6600 XT, built on the RDNA 2.0 architecture with a 7 nm process, shows its strength in this title through consistent high averages. The GPU's boost clock of 2589 MHz and game clock of 2359 MHz are relatively high, and the data shows that these clocks translate well to Roblox's moderate graphical load. The card's 2048 shading units and 64 ROPs deliver a pixel rate of 165.7 GPixel/s and a texture rate of 331.4 GTexel/s, which are more than adequate for the sandbox genre's blocky geometry and simple textures. The GPU's performance percentile of 71 versus all GPUs, combined with an average benchmark score of 27985, places it in a solid mid-range tier, and the measured FPS results confirm that position. Notably, the RX 6600 XT's nearest rival, the NVIDIA GeForce GTX 980 Ti, has an average score of 27956 with a deltaPct of 0.1, meaning the two cards are statistically tied in raw compute. Yet in Roblox, the RX 6600 XT's modern architecture and higher memory bandwidth (256.0 GB/s) allow it to maintain frame rates above 200 FPS at 1080p Medium, a feat that older architectures would struggle to match due to driver overhead and lack of optimization. The GPU's 8 GB of GDDR6 memory on a 128-bit bus is not stressed by Roblox, evidenced by the fact that the gap between Low and High settings at 1440p is only 38.7 FPS, suggesting that memory capacity is not the bottleneck. The data indicates that the GPU's role is most critical at 4K, where the 93.2 FPS at High settings is only 14.5 FPS below the Low preset, showing that the card's compute units are fully engaged.

CPU Role

The Intel Core i5-9400, a 6-core, 6-thread Coffee Lake processor with a base clock of 2.90 GHz and boost clock of 4.10 GHz, plays a supporting role in Roblox's performance. The CPU's percentile rank of 50 versus all CPUs, with an average benchmark score of 2305, places it in the middle of the pack, but the measured FPS data shows that it is rarely the limiting factor in this game. At 1080p Low, the 307.5 FPS result is likely near the engine's render thread limit, as the CPU's single-core performance (Cinebench R23 single-core score of 1125) is adequate but not exceptional. The CPU's nearest rival, the Intel Core i3-10305, has an average score of 2300 with a deltaPct of 0.2, indicating they are essentially equivalent in compute, and the data suggests that swapping between them would yield no measurable difference in Roblox. The 6-core/6-thread configuration is sufficient for Roblox's physics and scripting, which typically use fewer than four threads, but the lack of hyper-threading means that background tasks could interfere with frame pacing. The CPU's 9 MB of shared L3 cache and dual-channel DDR4 memory support at 42.7 GB/s provide enough bandwidth to feed the GPU at 1440p, as evidenced by the 167 FPS at High settings. However, the data shows that the CPU begins to matter more at 4K Ultra, where the 78.7 FPS result is likely a combination of GPU load and CPU draw-call overhead. The boost clock of 4.10 GHz on the i5-9400 is the key enabler for high minimum frame rates, and the measured averages suggest that the processor can keep up with the GPU's output until the pixel fill rate becomes the sole bottleneck. The CPU's 65 W TDP and 14 nm process node are dated by modern standards, but for Roblox, the processor's age is irrelevant because the game's single-threaded nature favors the boost clock over core count.

Settings Recommendations

The measured rows provide a clear hierarchy for optimizing the experience. At 1080p, the Low preset delivers 307.5 FPS, but this is unnecessary for most displays, and the Medium preset at 277.9 FPS offers a better balance of visual fidelity and headroom. The Ultra preset at 198.1 FPS is still exceptionally smooth and provides the best visual quality for the least performance cost at this resolution. At 1440p, the High preset at 167 FPS is the recommended choice, as it maintains frame rates above 165 Hz while offering improved shadows and effects over Medium. The Ultra preset at 134.6 FPS is playable and looks superior, but the 32.4 FPS drop from High to Ultra is steep for marginal visual gains. At 4K, the Medium preset at 105 FPS is the sweet spot, providing a smooth experience that exceeds 100 FPS while avoiding the 14.3 FPS penalty of High and the 26.3 FPS penalty of Ultra. The Low preset at 4K (116.4 FPS) is not worth the visual downgrade, as the GPU has enough headroom to handle Medium without sacrificing frame rates. Across all resolutions, the data shows that Ultra is never the best choice for competitive play, as the frame rate drops of 26.3% at 4K, 19.4% at 1440p, and 28.7% at 1080p versus Medium are too large relative to the visual improvements. For users with 144 Hz displays, 1440p High is the optimal combination, delivering 167 FPS with a 1.21 safety margin over the refresh rate. For 4K displays with 60 Hz panels, any preset above Low provides more than enough performance, making Ultra the viable choice for maximum visual quality.

How This Combo Ranks

In the database of tested combinations, this pairing of the Intel Core i5-9400 and AMD Radeon RX 6600 XT ranks 1307 out of 1800 combos in Roblox, placing it in the 72nd percentile of all tested systems. This rank is surprisingly low given the absolute frame rates achieved, but it reflects the fact that Roblox's performance is heavily dependent on CPU single-thread speed, and many newer processors with higher boost clocks and IPC gains outpace the i5-9400. The GPU's rank in the overall database is higher than the combo's rank, with the RX 6600 XT sitting in the 71st percentile versus all GPUs, while the CPU is in the 50th percentile. This discrepancy suggests that the combo's rank is dragged down by the processor's age, not the graphics card's capability. The data shows that the combo's performance is sufficient to beat the majority of systems, but it does not reach the top tier because the CPU's 4.10 GHz boost clock is not competitive with newer 5.0 GHz+ parts. The measured FPS results indicate that the combo is overqualified for 1080p gaming, where it delivers 307.5 FPS at Low settings, but the rank of 1307 means that many other systems achieve even higher frame rates, likely due to newer CPUs with better single-thread performance. The GPU's nearest rival, the NVIDIA GeForce RTX 3070, has a deltaPct of -0.9, meaning the RTX 3070 is 0.9% slower in average benchmark score, yet in Roblox, the RX 6600 XT's 8 GB VRAM and RDNA 2.0 architecture may not translate to a rank advantage because the game is not GPU-limited at lower resolutions. The combo's rank of 1307 out of 1800 places it in the upper-middle tier, and the data suggests that upgrading the CPU to a newer 6-core part with higher IPC would push the combo into the top 500, while the GPU has ample headroom to benefit from such a change.