Change flight simulator settings first, identify CPU, GPU, VRAM or streaming bottlenecks, and learn when a PC upgrade will fix choppy performance.
For PC flight simulators in general, change settings before upgrading your computer. Use the simulator’s frame-time or developer overlay to identify whether the main CPU thread, GPU, VRAM, RAM, storage or scenery streaming is responsible. Upgrade only when targeted changes and a sensible frame cap cannot deliver acceptable, consistent performance.
A mistake we see constantly is buying a faster graphics card because the FPS is low, even though the simulator is limited by one CPU thread. Average FPS alone is also misleading: uneven frame times, add-on pauses and display synchronisation can make a nominally fast simulator look choppy.
How do I find the flight simulator bottleneck?
The correct fix comes from identifying which part of each frame takes longest, not from comparing the PC with a generic recommended specification.
- Create a repeatable test. Use the same aircraft, airport, weather, camera view and traffic conditions. Test a demanding situation that represents how you normally fly, not an empty runway that conceals the problem.
- Establish a clean baseline. Restart the simulator, close recording and monitoring tools you do not need, and temporarily disable third-party aircraft, scenery and external utilities. If the stock configuration is smooth, reintroduce add-ons in groups.
- Read frame times. Use the simulator’s built-in performance display where available. Microsoft Flight Simulator can report limits such as
MainThreadand GPU; other simulators expose CPU and GPU frame times or can be checked with a hardware monitor. Lower frame time is better, and total CPU utilisation can hide one saturated logical core. - Run controlled setting tests. Lower resolution or render scaling substantially, then retest. A clear improvement points to the GPU. Restore it and reduce terrain detail, object detail and traffic; improvement there points towards the CPU or main simulation thread.
- Check behaviour over time. If performance begins smoothly and deteriorates, inspect temperatures, clock speeds, committed memory and disk activity. Thermal throttling, page-file pressure or a misbehaving utility is a fault to correct before replacing hardware.
| Likely limit | Typical evidence | Change first | Upgrade signal |
|---|---|---|---|
| Main CPU thread | The overlay reports a main-thread limit, GPU load falls, and reducing resolution barely changes FPS. | Lower terrain or object detail, autogen, AI traffic, road traffic and complex cockpit refresh rates. | Those settings must be reduced below an acceptable level in normal flying. |
| GPU | GPU frame time is highest, utilisation remains near full, and lower resolution or render scaling gives a clear gain. | Reduce render scaling, clouds, shadows, reflections, ambient occlusion or anti-aliasing quality. | Acceptable performance requires an image quality or resolution compromise you do not want. |
| VRAM | Hitches appear while panning or loading detailed airports, often with texture swapping near the card’s memory limit. | Lower texture resolution, render resolution and memory-heavy scenery. | Normal aircraft and airports repeatedly exceed practical VRAM capacity. |
| System RAM | Committed memory approaches physical capacity and paging rises, especially during long flights or with many utilities open. | Close background applications, remove suspect add-ons and keep the Windows page file enabled. | Normal use creates repeatable memory pressure after software faults have been excluded. |
| Storage or content | Pauses coincide with asset loading, heavy disk activity or one particular scenery package. | Test without the add-on and move the simulator from a hard disk to an SSD if applicable. | The storage device cannot supply assets promptly; this does not explain consistently low CPU- or GPU-bound FPS. |
| Streaming connection | Streamed scenery degrades or produces data warnings while local CPU and GPU frame times remain reasonable. | Check bandwidth, network stability, online-data settings and the simulator’s cache. | A PC component upgrade is usually not the answer. |
| Frame pacing | The FPS counter looks healthy but motion judders, with uneven frame-time delivery or a refresh-rate mismatch. | Apply one stable frame cap and configure V-Sync or variable refresh correctly. | Usually none; diagnose synchronisation before buying hardware. |
Modern Microsoft Flight Simulator workloads mix simulation, rendering, streamed scenery and add-ons, so our breakdown of what loads each PC component in MSFS helps interpret these symptoms.
Which flight simulator settings should I change first?
Change only the settings associated with the measured bottleneck; applying a Low preset hides the cause and often sacrifices quality that was not affecting performance.
Main-thread and CPU settings
Start with terrain and object level of detail, scenery or autogen density, AI aircraft, road traffic and other moving-world objects. Complex aircraft systems and glass-cockpit displays can also increase main-thread load, so compare a default aircraft with the one that causes trouble.
For Microsoft Flight Simulator 2024, use our MSFS 2024 bottleneck and settings workflow to separate MainThread, GPU, VRAM and streaming limits. In older FSX installations, CPU-heavy autogen and AI traffic are common culprits; our practical FSX tuning order for autogen, traffic and clouds covers those trade-offs.
GPU and VRAM settings
Resolution and render scaling are the quickest GPU tests. After that, reduce volumetric clouds, shadow quality, reflections, ambient occlusion and demanding anti-aliasing options one at a time.
Texture resolution often has little effect on FPS while sufficient VRAM remains available, but it can cause severe hitching once detailed aircraft and airports push memory too far. Monitoring tools may report allocated rather than actively required VRAM, so confirm the diagnosis by reducing textures and repeating the same flight.
Stutters caused by add-ons, storage or memory
Short pauses are not always a graphics problem. Test without custom scenery, traffic injectors, weather tools and complex aircraft; a single add-on can create main-thread spikes or load oversized textures regardless of the base simulator settings.
An SSD can improve loading and asset delivery, but it will not correct a sustained CPU or GPU frame-time limit. Likewise, adding RAM helps only when the system is genuinely paging or exhausting available memory; unused RAM being employed as a file cache is normal.
Why is the simulator choppy even when FPS is high?
High average FPS can still look choppy when frames arrive unevenly or do not align with the monitor’s refresh cycle.
Set a cap the computer can maintain in your demanding test, rather than allowing FPS to swing between high and low values. With variable refresh, keep delivery within the display’s supported range; on a fixed-refresh monitor, a stable rate that divides evenly into the refresh rate can look smoother than a higher fluctuating rate.
Use only one primary limiter. Stacking the simulator limiter, driver limiter and an overlay limiter can create inconsistent pacing. NVIDIA users can apply our driver-level frame-cap, V-Sync and G-SYNC guidance for MSFS before considering new hardware.
Frame generation can increase displayed FPS in simulators that support it, but it needs a sufficiently stable base frame rate. It cannot remove main-thread stalls, scenery-loading pauses or simulation latency.
When is a PC upgrade the right fix?
A PC upgrade is justified when testing identifies the same hardware bottleneck repeatedly and the settings needed to avoid it produce an unacceptable result.
- The problem occurs in representative flights, not only in one unusually demanding or faulty add-on.
- Temperatures, power settings, drivers and background software have been checked.
- A clean simulator configuration shows the same limitation.
- Targeted settings improve performance, proving which component is responsible.
- The proposed upgrade is large enough to address that component rather than shifting the bottleneck slightly.
Choose a CPU or platform upgrade for persistent main-thread limits, and a GPU upgrade when lowering resolution or render scaling produces a strong improvement. Add RAM only for measured memory pressure, choose an SSD for hard-disk loading stalls, and treat streamed-scenery network problems as a connection or cache issue rather than a reason to replace the PC.