Microsoft Flight Simulator

Microsoft Flight Simulator is an exceptionally demanding title, and the combination of the Intel Core i5-9400 and NVIDIA GeForce RTX 4080 creates a fascinating bottleneck scenario. The data shows a system where the GPU is clearly capable of high frame rates, but the six-core, six-thread CPU from 2018 frequently limits performance, especially at lower resolutions. This analysis focuses strictly on the measured results, providing a practical guide for what settings to use and what performance to expect from this specific pairing.

Settings Recommendations

The measured FPS rows provide a clear hierarchy for this CPU and GPU pairing across all three tested resolutions. At 3840x2160 (4K), the Medium preset emerges as the optimal choice. It delivers an average of 97 FPS with a minimum of 83 FPS and a maximum of 112 FPS. This is a significant jump from the High preset, which averages 73 FPS, and the Ultra preset, which averages 70 FPS. The Low preset at 4K does hit 108 FPS, but the visual fidelity loss is substantial for only an 11 FPS gain over Medium. The Medium preset's min FPS of 83 is also the only 4K setting with a recorded minimum, suggesting it provides a more stable frame time experience than the other presets, which have null min/max values.

For 2560x1440 (1440p), the High preset is the sweet spot. It delivers an average of 98 FPS, which is only 9 FPS lower than the Low preset's 119 FPS but offers considerably better visual quality. The Ultra preset at 1440p drops to 95 FPS, making High the best balance of fidelity and performance. The Medium preset at 1440p, averaging 109 FPS, is also viable, but High provides a more substantial visual upgrade for a relatively small performance cost. The data indicates that at this resolution, the GPU still has enough headroom to handle increased graphical loads without a drastic FPS penalty.

At 1920x1080 (1080p), the High preset is the recommended choice. It achieves an average of 105 FPS, which is just 1 FPS more than the Ultra preset's 104 FPS. This suggests that at 1080p, the CPU is the limiting factor, and the graphical preset has a minimal impact on the average frame rate. The Low preset reaches 128 FPS, but this is a CPU-bound result, not a GPU one. The performance difference between High and Ultra at 1080p is negligible, so opting for Ultra is a valid choice for maximum visual fidelity, but High is the most efficient setting to ensure consistent performance without overloading the CPU.

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. This Coffee Lake architecture chip has a 9 MB shared L3 cache and a dual-channel DDR4 memory interface with 42.7 GB/s of bandwidth. Its benchmark scores place it in the 47th percentile of all CPUs, with an average score of 2254. It sits directly between rivals like the Intel Core i7-1068NG7 (deltaPct -0.2) and the AMD Ryzen 5 PRO 1500 (deltaPct 0.4), indicating it is a mid-tier performer in synthetic tests.

In Microsoft Flight Simulator, the CPU's role is pivotal for physics, flight systems, and draw call management. The data shows that the i5-9400 is a limiting factor at 1080p. The difference in average FPS between the Low (128 FPS) and Ultra (104 FPS) presets at 1080p is 24 FPS, but the difference between High (105 FPS) and Ultra (104 FPS) is only 1 FPS. This near-flat performance curve from High to Ultra strongly suggests that the GPU is not the bottleneck; the CPU is unable to feed the RTX 4080 with enough data to produce higher frame rates. The CPU's 6 threads are likely being fully utilized, creating a hard ceiling on performance.

At higher resolutions, the CPU bottleneck becomes less severe as the GPU takes on more rendering work. The scaling from 1080p High (105 FPS) to 1440p High (98 FPS) is a drop of only 7 FPS, and then to 4K High (73 FPS) is a further drop of 25 FPS. This pattern indicates that as resolution increases, the GPU's workload becomes the primary constraint, allowing the CPU to keep up more effectively. The i5-9400's performance is adequate to drive the RTX 4080 at 4K, but it prevents the system from fully utilizing the GPU's potential at 1080p.

FAQ

Q: Is the Intel Core i5-9400 a bottleneck for the RTX 4080 in this game?

A: Yes, the data strongly indicates a CPU bottleneck at 1920x1080. The average FPS is nearly identical between the High (105 FPS) and Ultra (104 FPS) presets, and the Low preset only reaches 128 FPS. This flat performance scaling suggests that the 6-core, 6-thread CPU is the limiting factor, preventing the GPU from pushing higher frame rates.

Q: What is the best resolution to use to avoid the CPU bottleneck?

A: The data suggests 2560x1440 is the best compromise. At this resolution, the High preset delivers 98 FPS, and the performance difference between presets is more pronounced (Low at 119 FPS, Ultra at 95 FPS), indicating the GPU is becoming more engaged. The 4K results show the GPU is the primary bottleneck, but the overall frame rates are lower.

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

A: The i5-9400 has an average benchmark score of 2254. It is nearly identical in performance to the Intel Core i7-1068NG7, which scores 2259 (deltaPct -0.2), and the Intel Core i7-10710U, which scores 2248 (deltaPct 0.3). It also sits close to the AMD Ryzen 5 PRO 1500 (score 2246, deltaPct 0.4) and the Intel Core i3-10305 (score 2264, deltaPct -0.4). These are all very close scores, indicating the i5-9400 is a solid mid-range performer.

Q: What is the performance difference between the Low and Ultra presets at 4K?

A: At 3840x2160, the Low preset averages 108 FPS, while the Ultra preset averages 70 FPS. This is a 38 FPS difference. The Medium preset offers a middle ground at 97 FPS, which is a much better trade-off than Low, as it provides improved visuals for only an 11 FPS decrease.

Q: Does the RTX 4080 have a high percentile ranking among all GPUs?

A: Yes, the NVIDIA GeForce RTX 4080 is in the 86th percentile of all GPUs, with an average benchmark score of 54247. Its nearest rival is the NVIDIA GeForce RTX 4080 SUPER, which scores 54209 (deltaPct 0.1), showing they are essentially performance equals in synthetic tests.

Q: Is there a specific setting at 1440p that offers the best stability?

A: The Medium preset at 2560x1440 is the only one with recorded min/max values, showing a minimum of 92 FPS and a maximum of 125 FPS. While the High preset has a higher average of 98 FPS, the Medium preset's data suggests it has a more defined and stable frame rate range, which can be beneficial for consistent gameplay.

How This Combo Ranks

The combination of the Intel Core i5-9400 and NVIDIA GeForce RTX 4080 holds a rank of 776 out of 3714 tested combos in Microsoft Flight Simulator. This places it in the top 20.9% of all tested systems. This is a strong ranking, but it is important to contextualize it. The high rank is largely attributable to the RTX 4080's impressive raw power, which is in the 86th percentile of all GPUs. The CPU, however, is only in the 47th percentile, which drags the combo down from what it could achieve with a more modern processor.

The data suggests that this combo performs better than the sum of its parts might indicate, but it is still limited by the older CPU. A system with a higher-ranked CPU would likely push this combo significantly higher in the rankings. The rank of 776 indicates that while many systems are slower, a substantial number of combinations are faster, primarily due to having a more balanced or more powerful CPU. This is a clear case where the GPU is doing the heavy lifting in the ranking, but the CPU prevents the combo from reaching the top echelons of performance.

Resolution Scaling

The measured FPS data shows a clear and expected pattern of performance scaling across resolutions. At the High settings preset, the average FPS drops from 105 at 1920x1080 to 98 at 2560x1440, and then to 73 at 3840x2160. This represents a 6.7% drop from 1080p to 1440p, and a 30.5% drop from 1080p to 4K. The relatively small drop from 1080p to 1440p, followed by a larger drop to 4K, is a classic sign of a CPU bottleneck at lower resolutions.

At 1080p, the CPU is the primary limiting factor. The system is unable to fully utilize the RTX 4080, which is why the FPS is relatively low and does not scale much with graphical settings. As the resolution increases to 1440p, the GPU begins to take on more work, and the FPS drop is moderate. At 4K, the GPU becomes the definitive bottleneck. The RTX 4080 is working much harder to render the higher pixel count, and the FPS drops significantly. The scaling from 1440p to 4K shows the GPU's performance limits, while the scaling from 1080p to 1440p shows the CPU's limitations. This analysis confirms that to maximize the RTX 4080's potential, a 1440p or 4K monitor is required.

Measured FPS Breakdown

Here is the complete breakdown of the measured average FPS data, with min and max values where available.

1920x1080

• Low: 128 FPS average
• Medium: 117 FPS average (min 99, max 134)
• High: 105 FPS average
• Ultra: 104 FPS average

At 1080p, the Low preset provides the highest frame rate at 128 FPS. The Medium preset offers a stable performance window between 99 and 134 FPS. The High and Ultra presets are nearly identical, with a difference of only 1 FPS, highlighting the CPU bottleneck.

2560x1440

• Low: 119 FPS average
• Medium: 109 FPS average (min 92, max 125)
• High: 98 FPS average
• Ultra: 95 FPS average

At 1440p, the Low preset drops to 119 FPS, while Medium provides a stable range of 92-125 FPS. The High preset averages 98 FPS, and Ultra trails slightly at 95 FPS. The performance gap between Low and Ultra is now 24 FPS, indicating that the GPU is playing a larger role.

3840x2160

• Low: 108 FPS average
• Medium: 97 FPS average (min 83, max 112)
• High: 73 FPS average
• Ultra: 70 FPS average

At 4K, the Low preset maintains a high 108 FPS average, but the Medium preset provides a more balanced experience at 97 FPS. The High and Ultra presets are the most demanding, with averages of 73 FPS and 70 FPS respectively. The significant drop from Medium to High at 4K demonstrates the substantial increase in GPU load required for the higher visual fidelity settings.