Microsoft Flight Simulator

The Intel Core i5-9400 and NVIDIA GeForce GTX 1660 Ti pairing in Microsoft Flight Simulator represents a mid-range configuration that struggles to maintain smooth frame rates at higher resolutions but shows its strengths at 1080p. The data reveals a system where the GPU is the primary bottleneck at 4K, while the CPU holds up adequately at lower settings.

CPU Role

The Intel Core i5-9400 provides six physical cores and six threads, a configuration that lacks hyper-threading but offers a solid foundation for a flight simulator. Its base clock of 2.90 GHz and boost clock of 4.10 GHz are modest by modern standards, yet the Coffee Lake architecture’s 9 MB of shared L3 cache helps with the streaming-heavy workloads that Microsoft Flight Simulator generates. In synthetic benchmarks, the processor scores 803 in Cinebench R15 multi-core and 113 in single-core, with a more modern Cinebench R23 result of 7969 multi-core and 1125 single-core. These figures place the i5-9400 at the 50th percentile among all CPUs, meaning it sits exactly in the middle of the pack.

Comparing against its nearest rivals, the i5-9400’s average benchmark score of 2305 is just 0.2% ahead of the Intel Core i3-10305 and the Intel Core i3-1125G4, both of which score around 2300. It also edges out the Intel Xeon E-2134 by 0.4%, while trailing the Intel Core i7-8809G by 0.6%. These tiny margins indicate that the i5-9400 is not a performance outlier; it is a competent but unremarkable six-core processor that delivers consistent results without dominating any specific workload. In the context of Microsoft Flight Simulator, the CPU’s role is to feed the GPU with terrain and aircraft data, and the benchmark results suggest it does so adequately at lower resolutions but may struggle to keep up with the most demanding scenery at 4K.

GPU Role

The NVIDIA GeForce GTX 1660 Ti is built on the Turing architecture using a 12 nm process from TSMC, packing 6,600 million transistors into a 284 mm² die. It ships with 6 GB of GDDR6 memory on a 192-bit bus, providing 288.0 GB/s of bandwidth. The GPU’s base clock is 1500 MHz, boosting to 1770 MHz, while memory runs at 1500 MHz with 12 Gbps effective speed. With 1536 shading units, 96 TMUs, and 48 ROPs, the GTX 1660 Ti delivers 5.437 TFLOPS of FP32 performance and a pixel rate of 84.96 GPixel/s. It places at the 55th percentile among all GPUs, with an average benchmark score of 13925.

The GTX 1660 Ti’s nearest rivals are closely matched. The AMD Radeon RX 570X scores 13871, putting it 0.4% behind, while the NVIDIA Tesla K10 scores 14029, which is 0.7% ahead. The NVIDIA RTX A2000 Mobile and GeForce GTX 680 trail by 0.8%, scoring 13821 and 13812 respectively. These narrow deltas show that the GTX 1660 Ti is a solid mid-tier card that competes well with its contemporaries. In Microsoft Flight Simulator, the GPU’s 6 GB of VRAM is a critical factor; at 4K Ultra settings, the game’s texture demands can push memory usage to its limits, which likely contributes to the low frame rates observed at that resolution.

Resolution Scaling

The measured FPS data shows a clear and predictable scaling pattern as resolution increases from 1080p to 4K. At 1080p with Low settings, the combo achieves 76.6 FPS, which drops to 65.8 FPS at 1440p and further to 46.9 FPS at 4K. This represents a 38.8% drop from 1080p to 4K at Low settings. The Medium settings follow a similar trajectory: 62.6 FPS at 1080p, 47.3 FPS at 1440p, and 34.1 FPS at 4K, a 45.5% reduction. High settings see 47.2 FPS at 1080p, 34.4 FPS at 1440p, and 29.9 FPS at 4K, a 36.7% drop. Ultra settings are the most demanding, starting at 44.9 FPS at 1080p, falling to 37.5 FPS at 1440p, and bottoming out at 25 FPS at 4K — a 44.3% decrease.

The scaling pattern indicates that the GPU becomes the limiting component as resolution climbs. At 1080p, the i5-9400 can keep the GTX 1660 Ti fed, as evidenced by the relatively high frame rates. However, at 4K, the frame rates collapse, particularly at Ultra settings where the 25 FPS result is barely playable. The gap between Low and Ultra settings widens with resolution: at 1080p, the difference is 31.7 FPS (76.6 vs 44.9), while at 4K, it narrows to 21.9 FPS (46.9 vs 25). This suggests that at higher resolutions, the GPU’s raw compute power and memory bandwidth are the primary constraints, and the CPU’s role diminishes.

How This Combo Ranks

In the database of tested combinations for Microsoft Flight Simulator, the Intel Core i5-9400 with the GTX 1660 Ti ranks 1550 out of 1795 combos. This places it in the bottom 13.6% of all tested configurations, which is a surprisingly low position given the hardware’s mid-range specifications. The rank reflects the game’s extreme demands on both CPU and GPU, and the i5-9400’s lack of hyper-threading likely hurts it in this simulation-heavy title, which can utilize more threads for complex flight models and weather calculations.

The combo’s rank suggests that while the individual components are not weak — the CPU sits at the 50th percentile and the GPU at the 55th — their combined performance in this specific game is subpar. This discrepancy highlights the importance of testing hardware in context; a combination that performs well in synthetic benchmarks may not translate to playable frame rates in a demanding flight simulator. The 1550th position out of 1795 combos indicates that many other pairings, including those with older or lower-tier components, manage to outperform this setup in Microsoft Flight Simulator, likely due to better CPU-GPU balance or more efficient memory configurations.

Measured FPS Breakdown

At 1080p, the combo delivers its best results. Low settings produce an average of 76.6 FPS, which is smooth and playable. Medium settings drop to 62.6 FPS, still acceptable for a flight simulator. High settings yield 47.2 FPS, which is playable but with noticeable stutters in dense areas. Ultra settings fall to 44.9 FPS, which is borderline for a game that benefits from stable frame rates. These numbers suggest that 1080p is the sweet spot for this combo, with Low and Medium settings providing the most enjoyable experience.

Moving to 1440p, the frame rates become more marginal. Low settings achieve 65.8 FPS, which is still decent, but Medium drops to 47.3 FPS, and High falls to 34.4 FPS. Ultra settings produce 37.5 FPS, which is below the threshold for smooth gameplay. The 1440p results indicate that the GTX 1660 Ti’s 6 GB of VRAM and 192-bit memory bus are insufficient for maintaining high frame rates at this resolution with higher quality settings.

At 4K, the combo struggles significantly. Low settings produce 46.9 FPS, which is playable but not ideal. Medium settings drop to 34.1 FPS, High to 29.9 FPS, and Ultra to 25 FPS. These numbers are all below the 60 FPS target that many players prefer, and the 25 FPS result at Ultra is particularly poor. The 4K data confirms that this combo is not suited for high-resolution gaming in Microsoft Flight Simulator, and users seeking 4K performance would need a significantly more powerful GPU.

The overall pattern across all resolutions and settings shows that the combo is best utilized at 1080p with Medium or Low settings, where it can maintain frame rates above 60 FPS. At higher resolutions, the GPU becomes the limiting factor, and the experience degrades rapidly. The data also shows that the CPU is not the primary bottleneck in most scenarios, as the frame rate drops are more pronounced when resolution increases rather than when settings are raised, which points to GPU limitations. This combo is a capable 1080p solution for Microsoft Flight Simulator but falls short at higher resolutions.