Roblox

How This Combo Ranks

The Intel Core i5-9400 paired with the NVIDIA GeForce RTX 5090 ranks 220th out of 3711 tested combos in Roblox. That places this configuration in the top 6% of all tested systems for this game, a strong result driven almost entirely by the GPU. The CPU itself sits at the 47th percentile among all processors in the database, while the GPU sits at the 92nd percentile among all graphics cards. This gap in percentile standing is the first clear signal that the RTX 5090 is doing the heavy lifting here.

Looking at the CPU's nearest rivals, the i5-9400 posts an average benchmark score of 2254, which is nearly identical to the Intel Core i7-1068NG7 at 2259, the Intel Core i7-10710U at 2248, and the AMD Ryzen 5 PRO 1500 at 2246. The Intel Core i3-10305 sits slightly higher at 2264. All four rivals are within 0.4% of the i5-9400's score, so the CPU is essentially mid-pack among its direct competitors. The RTX 5090, meanwhile, posts an average benchmark score of 79842, with its nearest rivals including the NVIDIA Tesla P100 PCIe 16 GB at 79605, the NVIDIA Tesla P100 PCIe 12 GB at 79396, the AMD Radeon RX 6850M XT at 78940, and the AMD Radeon Pro Vega 64X at 80959. The GPU is 1.4% ahead of the slowest rival and 1.4% behind the fastest, a tight grouping that shows the 5090 is squarely in high-end territory.

The combination of a mid-range CPU and an elite GPU produces a lopsided system, but for Roblox specifically, the data shows this lopsidedness is not a problem. The recorded FPS figures are extraordinarily high across every resolution and preset, which suggests the game is not demanding enough to expose the CPU as a bottleneck. The combo rank of 220 out of 3711 reflects the overall capability of the pair, and in this title, the pair is clearly capable of far more than the game requires.

CPU and GPU Roles

The data reveals a clear pattern: the GPU is the dominant component in this pairing for Roblox, but the CPU still matters for maintaining high frame rates at lower resolutions. At 1920x1080, the difference between Low and Ultra settings is 554.3 FPS versus 476.8 FPS, a gap of 77.5 FPS. At 2560x1440, the same comparison shows 483.5 FPS versus 322.9 FPS, a gap of 160.6 FPS. At 3840x2160, Low delivers 277.1 FPS while Ultra delivers 179.5 FPS, a gap of 97.6 FPS. The largest spread between Low and Ultra occurs at 1440p, which suggests that at this resolution the settings are having the most pronounced effect on performance.

Scaling from 1080p to 1440p, the average FPS across all settings drops by roughly 15-20%, while scaling from 1440p to 4K produces a much larger drop of roughly 40-45%. For example, High settings go from 512.3 FPS at 1080p to 396.5 FPS at 1440p, then down to 227.2 FPS at 4K. This pattern indicates that the GPU becomes increasingly stressed as resolution rises, which is expected behavior for a modern graphics card running a lightweight sandbox title.

The CPU's role is more apparent at 1080p, where the frame rates are so high that the i5-9400's six cores and six threads are likely near their limit. The fact that 1080p Low hits 554.3 FPS while 1080p Ultra still manages 476.8 FPS suggests the CPU is keeping up with even the most demanding preset at this resolution. At 4K, the GPU takes over as the primary limiting factor, and the CPU's contribution becomes less critical. The data supports the conclusion that for Roblox, the RTX 5090 is the star of this show, but the i5-9400 is not holding it back in a meaningful way.

Measured FPS Breakdown

At 3840x2160, the recorded average frame rates are as follows: Low settings deliver 277.1 FPS, Medium delivers 255.8 FPS, High delivers 227.2 FPS, and Ultra delivers 179.5 FPS. The gap between Low and Ultra is 97.6 FPS, which is substantial but still leaves every preset far above the 60 FPS playability threshold. The progression from Low to Ultra is not perfectly linear, as the step from Low to Medium costs 21.3 FPS, while the step from Medium to High costs 28.6 FPS, and the step from High to Ultra costs 47.7 FPS. The largest performance hit comes from moving to Ultra, which is consistent with the expectation that the highest preset introduces the most demanding effects.

At 2560x1440, the numbers are significantly higher. Low settings produce 483.5 FPS, Medium produces 447.3 FPS, High produces 396.5 FPS, and Ultra produces 322.9 FPS. The spread from Low to Ultra is 160.6 FPS, the largest of any resolution tested. The step from Low to Medium costs 36.2 FPS, from Medium to High costs 50.8 FPS, and from High to Ultra costs 73.6 FPS. The pattern here shows that each settings tier has a more pronounced effect at 1440p than at 4K, which indicates the system has more headroom at this resolution to expose the differences between presets.

At 1920x1080, the frame rates are the highest recorded. Low settings reach 554.3 FPS, Medium reaches 534.5 FPS, High reaches 512.3 FPS, and Ultra reaches 476.8 FPS. The total spread from Low to Ultra is 77.5 FPS, the smallest of all three resolutions. This compression suggests that at 1080p, the CPU is beginning to limit the maximum achievable frame rate, preventing the GPU from stretching its legs as much as it does at higher resolutions. The step from Low to Medium costs 19.8 FPS, from Medium to High costs 22.2 FPS, and from High to Ultra costs 35.5 FPS. Even the largest drop, from High to Ultra, is smaller than the equivalent drop at 1440p or 4K.

All recorded figures are average FPS values, with no minimum or maximum frame rates provided in the data. This means the analysis relies on average performance, which for a game like Roblox is sufficient given how far above the 60 FPS threshold every setting sits.

The Verdict

This PC can run Roblox at every resolution and every preset tested, with a massive margin above the 60 FPS playability threshold. The verdict data is unambiguous: all four settings presets are marked as playable at 3840x2160, 2560x1440, and 1920x1080. At 4K Ultra, the system delivers 179.5 FPS, which is nearly three times the required threshold. At 1440p Ultra, it delivers 322.9 FPS, more than five times the threshold. At 1080p Ultra, it delivers 476.8 FPS, nearly eight times the threshold.

The minimum recorded average FPS across all tests is 179.5 FPS at 4K Ultra, which is still comfortably above 60 FPS. There is no scenario in the data where this combination drops below the playable threshold, and there is no preset that needs to be lowered to achieve smooth gameplay. For players who prioritize visual fidelity, the Ultra preset is viable at every resolution. For players who prioritize raw frame rates, the Low preset at 1080p delivers 554.3 FPS, which is well beyond what most displays can even show.

The i5-9400's age and mid-range standing do not matter in this context. The game's relatively simple rendering demands, combined with the RTX 5090's enormous compute resources, create a situation where the CPU is never the limiting factor at any resolution or preset. The verdict is simple: this combination is overkill for Roblox, but it is also fully capable of running the game at maximum settings with frame rates that exceed any reasonable expectation.

FAQ

Q: Can the Intel Core i5-9400 and NVIDIA GeForce RTX 5090 run Roblox at 4K Ultra settings?

A: Yes, the combination delivers 179.5 FPS at 3840x2160 with Ultra settings, which is well above the 60 FPS playability threshold.

Q: What is the highest average frame rate recorded for this combo in Roblox?

A: The highest average frame rate is 554.3 FPS, achieved at 1920x1080 with Low settings.

Q: How does the i5-9400 compare to its nearest rivals in the database?

A: The i5-9400 scores 2254 on average, which is within 0.4% of the Intel Core i7-1068NG7, Intel Core i7-10710U, AMD Ryzen 5 PRO 1500, and Intel Core i3-10305.

Q: Is the RTX 5090 a significant performance outlier compared to other GPUs?

A: The RTX 5090 scores 79842 on average, placing it at the 92nd percentile among all GPUs, with its nearest rivals all within 1.4% of its score.

Q: Which resolution shows the largest performance difference between Low and Ultra settings?

A: At 2560x1440, the gap between Low and Ultra is 160.6 FPS, the largest of any resolution tested.

Q: Does the CPU bottleneck the GPU at any resolution in Roblox?

A: The data suggests the CPU may limit maximum frame rates at 1920x1080, where the spread between Low and Ultra is the smallest, but even then the lowest recorded average is 476.8 FPS, so no playability issue exists.

Best Settings per Resolution

At 3840x2160, the best settings that stay at or above 60 FPS are Ultra, delivering 179.5 FPS. This is the most demanding preset at 4K, and it still clears the threshold by nearly 120 FPS. Players can run the game at maximum visual quality without any concern for performance.

At 2560x1440, the best settings are also Ultra, delivering 322.9 FPS. The margin above 60 FPS is even larger here, making this resolution and preset combination exceptionally smooth. There is no reason to lower settings at 1440p, as even the heaviest preset leaves enormous headroom.

At 1920x1080, the best settings are Ultra as well, delivering 476.8 FPS. This is the highest frame rate recorded at the Ultra preset across all resolutions, and it is more than seven times the playability threshold. The system is so fast at 1080p that the CPU becomes the limiting factor, but the result is still far beyond what any current display can fully utilize.