Learn why Microsoft Flight Simulator is so demanding on PC, what loads the CPU and GPU, and which settings deliver the biggest gains.
Microsoft Flight Simulator is demanding because it builds a globe-scale world in real time while simulating aircraft systems, weather, traffic and aerodynamics. It must stream and decompress scenery, prepare thousands of objects on the CPU, render them on the GPU, and hold large working sets in RAM and VRAM—often simultaneously.
What makes Microsoft Flight Simulator harder to run than a typical game?
The simulator combines several heavy workloads that conventional games usually handle separately or within a much smaller area.
- A world-scale environment: Terrain, aerial imagery, buildings, vegetation, airports and elevation data must be assembled wherever you fly. A conventional game can optimise a bounded level much more aggressively.
- Changing conditions: Clouds, lighting, shadows, reflections, wind and visibility cannot all be baked into the scenery because location, time and weather keep changing.
- Detailed simulation: Flight models, avionics, electrical and hydraulic systems, AI traffic and ground vehicles continue running alongside the graphics workload.
- Large viewing distances: From an aircraft, the visible area can extend far beyond what a ground-level game normally draws. Higher Terrain Level of Detail and Object Level of Detail settings increase both object count and CPU preparation work.
- Streamed data: Both MSFS 2020 and MSFS 2024 obtain world data online. MSFS 2024 streams more content on demand, reducing how much must be permanently installed but putting greater emphasis on a stable connection, storage cache and decompression pipeline.
Detailed airports create a particularly severe combination: many buildings and lights, complex aircraft systems, glass cockpits, traffic and nearby city scenery all compete for resources at low altitude.
Is Microsoft Flight Simulator CPU- or GPU-heavy?
Microsoft Flight Simulator can be limited by either component, although busy airports and high terrain detail commonly expose a CPU or main-thread limit.
| Component | Main workload | Typical sign of a limit |
|---|---|---|
| CPU | Flight simulation, avionics, traffic, draw calls and scenery preparation | Lowering resolution produces little improvement, especially at airports |
| GPU | Resolution, clouds, shadows, reflections, anti-aliasing and final rendering | Reducing render scale or cloud quality produces an immediate frame-rate gain |
| VRAM | Textures, geometry, frame buffers and high-resolution displays | Hitching or abrupt performance loss in dense scenery or at high resolutions |
| System RAM | Loaded scenery, simulator data, add-ons and background applications | Paging to disk, long pauses or worsening performance during a flight |
| SSD and connection | Local packages, cache access and streamed scenery | Slow loading, scenery pop-in or pauses as new areas are loaded |
The simulator does use multiple CPU cores, but some frame preparation must still be coordinated by a heavily loaded main thread. That thread can hold back the GPU even when total CPU utilisation looks modest. A fast processor is therefore not defined by core count alone; per-core performance, memory latency and the wider platform matter too.
Our MSFS PC hardware and component guide explains the practical requirements for MSFS 2020 and 2024 without treating the minimum specification as a performance target.
Why can a powerful PC still stutter in MSFS?
Stutters usually come from a short-lived bottleneck rather than a PC being uniformly too slow.
Entering a photogrammetry city, turning towards a detailed terminal or loading extra traffic can suddenly increase asset streaming and CPU work. VRAM exhaustion can force data to move between graphics and system memory, while insufficient RAM can trigger much slower paging to storage. Complex aircraft and add-ons may also add scripts, textures and objects that the base simulator did not have to process.
A mistake we see constantly is judging performance from one flight. A rural cruise in clear weather is not comparable with a large add-on airport under heavy cloud and traffic. Use the same aircraft, runway, weather, camera and traffic conditions when following our repeatable MSFS benchmarking method.
The developer FPS display can help identify whether the main thread or GPU is limiting a scene. A simpler test is to lower output resolution or Render Scaling temporarily: if the frame rate barely moves, the CPU side is probably the constraint. Frame generation may make movement look smoother, but it does not speed up the main thread, flight model or control response.
Which MSFS settings demand the most hardware?
Terrain detail, object detail, traffic, clouds and render resolution usually produce the largest performance changes, but they stress different parts of the PC.
| Setting | Main pressure | When to reduce it |
|---|---|---|
| Terrain Level of Detail | CPU and memory | When performance falls over cities or near the ground |
| Object Level of Detail | CPU, GPU and memory | When detailed airports and urban areas are much slower than cruise |
| AI, road, ship and airport traffic | Mostly CPU | When the main thread is limiting at busy locations |
| Cloud quality | Mostly GPU | When overcast weather causes a large drop |
| Render Scaling and output resolution | GPU and VRAM | When the GPU is fully occupied |
| Texture resolution | Mostly VRAM | When memory pressure appears in dense scenery |
Reducing everything to Low is rarely the best answer. Diagnose the limiting component, then adjust the settings that target it. Our setting-by-setting MSFS graphics recommendations give practical starting points for balancing image quality and performance.
Does internet speed affect Microsoft Flight Simulator FPS?
Internet speed mainly affects scenery delivery and visual quality rather than the GPU's raw rendering speed.
An inadequate or unstable connection can cause blurry ground imagery, delayed photogrammetry and visible scenery changes. Streaming, decompression and cache activity can also coincide with pauses, but buying a faster connection will not fix a persistent GPU or main-thread limit.
Use an SSD with adequate free space, avoid saturating the connection with other downloads and test briefly with online world data disabled if you need to isolate streaming from local performance. Disabling it permanently sacrifices much of the world detail. If image quality is the main symptom, follow our scenery streaming and blurriness checks rather than lowering unrelated graphics settings.
What PC upgrade helps Microsoft Flight Simulator most?
The best upgrade is the one that removes the measured bottleneck at the resolution, aircraft and locations you actually use.
- Choose a CPU or platform upgrade when lowering resolution has little effect and the main thread limits performance. First test lower Terrain LOD, Object LOD and traffic.
- Choose a faster GPU when reducing Render Scaling, resolution or clouds gives a clear improvement. Higher-resolution monitors and VR increase this workload sharply.
- Add RAM only when capacity is genuinely exhausted. Extra unused memory does not increase frame rate, but avoiding paging can remove severe pauses.
- Move the simulator and cache to an SSD if they are still on a mechanical drive. This improves loading and asset access more reliably than average FPS.
Microsoft Flight Simulator feels unusually demanding because no single component carries the whole workload. Maxing every slider forces the CPU, GPU, memory, storage and network pipeline to absorb their heaviest loads at once; balanced settings usually produce a better result than chasing an unrestricted maximum preset.