Use the best MSFS 2020 RTX 4090 settings for 4K, including TAA vs DLSS, Frame Generation, LOD, traffic and stutter fixes.
For an RTX 4090, run Microsoft Flight Simulator 2020 at native 4K with the Ultra preset, then set Terrain Level of Detail to 200 and traffic conservatively. Use TAA or DLAA for the clearest cockpit displays; choose DLSS Quality plus Frame Generation when smoother high-refresh output matters more than absolute sharpness.
Recommended RTX 4090 settings for MSFS 2020 at 4K
At 4K, begin with Ultra and alter only the settings that cause avoidable CPU load, cockpit blur or latency. These recommendations assume a reasonably modern processor; the RTX 4090 cannot compensate for a severe MainThread bottleneck.
| Setting | Recommended value | When to change it |
|---|---|---|
| Global Rendering Quality | Ultra, then Custom | Custom preserves the Ultra baseline while allowing the changes below. |
| Resolution | Native monitor resolution | Use 3840 x 2160 on a 4K display; do not force 4K on a 1440p monitor. |
| DirectX Version | DirectX 12 with Frame Generation | Without Frame Generation, compare DirectX 11 and 12 and retain whichever gives steadier frame times. |
| Anti-Aliasing | TAA or DLAA | Change to DLSS Quality if more GPU performance is needed. |
| Render Scaling | 100 | Lower it only when GPU-limited; raising it is supersampling and can become very expensive. |
| Terrain Level of Detail | 200 | Use 150 at dense airports. Try 250 to 300 only when the CPU has clear headroom. |
| Objects Level of Detail | 200 | Reduce to 150 around detailed airports or scenery packages. |
| Volumetric Clouds | Ultra | High is the first useful reduction when weather makes the GPU the limiting factor. |
| Texture Resolution | Ultra | The RTX 4090 has ample VRAM for standard 4K use, although unusually large add-ons can increase consumption. |
| Anisotropic Filtering | 16x | Leave this high; its performance cost on this GPU is negligible. |
| Buildings, Trees and Terrain Vector Data | Ultra | Reduce only after LOD and traffic if the MainThread remains overloaded. |
| Offscreen Terrain Pre-Caching | Ultra | This helps prevent visible scenery rebuilding while panning the camera. |
| Shadow Maps | 2048 | Lower shadows before textures if GPU load becomes excessive. |
| Ambient Occlusion and Reflections | Ultra | High offers a modest saving with less visual loss than lowering resolution. |
| Glass Cockpit Refresh Rate | High | Use Medium when complex avionics are contributing to a MainThread limit. |
| Ground Aircraft Density | 0 to 20 per cent | Keep it low at large hubs, especially with detailed airliners. |
| Road Vehicles, Ships and Ferries | 10 to 20 per cent | Higher values consume CPU time without materially improving flight visuals. |
| V-Sync | Off with a variable-refresh display | Use one frame cap or synchronisation method rather than stacking several limiters. |
Our full explanation of which MSFS settings load the CPU and GPU covers the less consequential options left at Ultra by this baseline.
Should an RTX 4090 use TAA, DLAA or DLSS?
Use DLAA or TAA for maximum cockpit clarity, and DLSS Quality when the GPU needs help sustaining a high output resolution. DLSS Balanced and Performance render from fewer pixels, so glass displays, taxiway markings and distant buildings can look softer or show temporal artefacts.
- DLAA: The best starting point for native-resolution anti-aliasing when it is available and performance is already sufficient.
- TAA: A sharp, dependable choice for instrument-heavy aircraft, particularly at 1440p or 4K with Render Scaling at 100.
- DLSS Quality: Best for 4K high-refresh flying, demanding weather, multi-monitor configurations or unusually heavy scenery.
- DLSS Balanced or Performance: Reserve these modes for extreme resolutions. They are usually unnecessary on an RTX 4090 at ordinary 1440p or 4K.
At 1440p, the simulator is more likely to be CPU-limited, so reducing DLSS quality will not fix low MainThread performance. Our resolution-specific comparison of DLSS modes and TAA explains the image-quality trade-offs in more detail.
Should DLSS Frame Generation be enabled?
Enable Frame Generation for smoother high-refresh output when the underlying frame rate is already stable; leave it off when minimum latency and completely clean instrument rendering matter more. Generated frames improve perceived motion but do not accelerate the flight model, avionics or MainThread.
Frame Generation on the RTX 4090 requires DirectX 12, Windows Hardware-Accelerated GPU Scheduling and a compatible NVIDIA driver. It can also be paired with native-resolution anti-aliasing, so using Frame Generation does not automatically mean accepting aggressive DLSS upscaling. Follow our exact HAGS, DirectX 12 and in-game activation sequence if the option is missing or greyed out.
Do not judge Frame Generation solely by the displayed FPS number. If camera movement looks smooth but controls still feel sluggish, the base frame rate is too low or unstable; reduce CPU-heavy settings rather than asking Frame Generation to conceal the problem.
Which MSFS settings should not be maxed out?
Do not automatically push Terrain Level of Detail to 400 or fill every traffic slider because the graphics card is powerful. Terrain LOD, object complexity, glass-cockpit refresh and traffic often load the processor more heavily than the GPU.
- Terrain LOD 400: Useful mainly at altitude with exceptional CPU headroom; it can cause severe frame-time spikes near detailed airports.
- Maximum airport traffic: Static and live aircraft, service vehicles and workers compete with avionics and scenery on the MainThread.
- DLSS Performance at 1440p: It reduces image quality while doing nothing for a CPU limit.
- Multiple frame limiters: Combining in-game V-Sync, a driver cap and another limiter can create uneven pacing.
- Excessive supersampling: Raising Render Scaling far above 100 can finally overwhelm even an RTX 4090, particularly with clouds and reflections at Ultra.
Why can MSFS 2020 still stutter with an RTX 4090?
An RTX 4090 cannot eliminate stutters caused by the CPU, scenery loading, online data or a problematic add-on. Use the simulator's developer FPS display to identify whether it reports a MainThread or GPU limitation before lowering image quality.
- If limited by MainThread: Reduce Terrain LOD to 150 or 200, Objects LOD to 150, lower airport traffic and change Glass Cockpit Refresh Rate from High to Medium.
- If limited by GPU: Select DLSS Quality, lower Volumetric Clouds from Ultra to High, then reduce reflections or shadows. Leave textures at Ultra unless VRAM usage is genuinely exhausted.
- If pauses occur while moving through scenery: Check online-data performance and the rolling cache. A damaged or stale cache can produce symptoms that graphics changes will not solve.
- If stutters affect one aircraft or airport: Test a default aircraft at a default airport, then temporarily remove relevant packages from the Community folder. This separates an add-on problem from a global graphics issue.
Our MainThread-versus-GPU troubleshooting method provides the next steps when the developer display shows a persistent bottleneck.