Find why a flight simulator loses FPS on long flights, stutters on landing or warns of low memory, with practical fixes for PC, Xbox and PS5.
Flight simulators lose FPS on long flights when RAM or VRAM pressure, traffic, add-ons, scenery caches or heat builds during the session. A gradual decline points to accumulated resources or throttling; a sudden drop on descent or landing usually points to the destination airport, weather, traffic or scenery loading.
Why does FPS fall as a flight gets longer?
The timing and shape of the slowdown usually reveal its cause. Compare FPS and frame time after loading, in cruise, before descent and after landing rather than relying on a single reading.
| What happens | Most likely cause | Best confirmation |
|---|---|---|
| FPS declines gradually throughout the flight | Increasing memory pressure, an add-on retaining data, accumulating traffic or thermal throttling | A simulator restart restores performance, or memory rises while clock speeds fall |
| FPS drops suddenly on descent or landing | Detailed airport scenery, buildings, traffic, weather or glass-cockpit workload | A fresh flight loaded at the same destination also runs poorly |
| Brief freezes occur but FPS recovers between them | Scenery streaming, storage access, cache activity, shader work or VRAM eviction | The graph shows isolated frame-time spikes rather than a sustained reduction |
| The flight falls to 10 FPS while overall CPU use looks low | One main simulation thread is saturated | One logical processor is heavily loaded while the GPU is not fully occupied |
| Performance worsens after several hours and clocks decline | CPU or GPU thermal or power throttling | Temperatures rise while operating frequencies fall below their earlier values |
Memory growth alone does not prove a leak. Simulators deliberately retain textures, terrain and compiled data for reuse. A leak becomes likely when committed memory keeps increasing under comparable conditions, does not settle after leaving an area and is cleared only by closing the simulator or removing a particular add-on.
Use the same display method throughout the test. Our guide to recording FPS and frame time consistently explains why average FPS can hide the pauses that make a flight feel rough.
How do I diagnose a long-flight FPS drop?
A controlled comparison between a completed flight and a freshly loaded destination separates accumulated problems from an airport that is simply demanding.
- Create a repeatable baseline. Use the same aircraft, airport, weather preset, traffic level, graphics settings and simulation rate. Record FPS, frame time, RAM, VRAM, CPU and GPU clocks after the simulator has settled.
- Load the destination directly. After the slow flight, close and reopen the simulator and start at the arrival airport under matching conditions. Poor performance in both sessions implicates the destination, aircraft or settings; smooth performance after the restart implicates something accumulated en route.
- Separate low FPS from stuttering. Sustained 15 FPS is a throughput problem. One-second pauses followed by normal performance are frame-time spikes and need a different investigation.
- Test without optional content. Disable third-party aircraft, scenery, liveries, plugins and external traffic, weather, map or telemetry tools. On PC, move packages out of the relevant add-on folder rather than deleting them.
- Use MSFS Safe Mode when offered. Microsoft Flight Simulator may offer Safe Mode after an abnormal shutdown. It temporarily excludes third-party Community and Marketplace content, making it a diagnostic tool rather than a performance preset. Do not deliberately crash the simulator to trigger it; disable optional content manually if necessary.
- Reduce traffic before stripping graphics quality. AI aircraft, airport workers, road vehicles, boats and multiplayer objects can overload the main thread. A traffic add-on that fails to remove distant objects may become progressively heavier over several hours.
- Check memory pressure. On PC, look for nearly exhausted physical RAM, rising committed memory and heavy paging. For VRAM pressure, correlate the reported allocation with stutters or performance recovery after lowering texture and scenery demands; a nearly full allocation by itself is not conclusive.
- Check clocks as well as temperatures. Heat is responsible only when the CPU or GPU reduces its operating frequency or the system displays a thermal warning. Desktop hardware normally reaches a steady temperature well before the end of a long-haul flight.
- Restore add-ons in groups. Re-enable half the disabled packages, repeat the test and keep narrowing the affected group. This finds a faulty package much faster than testing a large library one item at a time.
A controlled heen en terug test—Dutch for “there and back”—can also expose deterioration with elapsed session time. Returning to the departure airport is useful because its workload is already known, although a fresh destination load remains the cleaner comparison.
Is it low FPS or long-flight stuttering?
Low FPS is a continuous failure to render frames quickly enough, while stuttering consists of isolated frames that take far longer than the surrounding ones.
When MSFS 2024 freezes during flight and then catches up, investigate scenery downloads, storage activity, cache behaviour, add-ons and VRAM pressure. Lowering every graphics option may raise the average FPS without removing the pause. Our detailed process for diagnosing freezes and micro-stutters covers those frame-time problems separately.
Why does MSFS stutter on landing?
MSFS often stutters on landing because the simulator must introduce dense airport scenery, ground traffic, nearby aircraft, detailed terrain and changing weather while the cockpit systems continue running.
Load the same runway directly with a fixed weather preset. If it stutters from a fresh session, first reduce airport and AI traffic, terrain or object detail, and unusually heavy destination scenery. If the fresh load is smooth but the completed flight is not, concentrate on add-ons, traffic accumulation, memory pressure and the rolling or streamed scenery path.
Live weather makes comparisons unreliable because cloud layers and visibility may change between tests. Increased simulation rate can also leave scenery streaming and aircraft systems trying to catch up, so repeat the approach at normal speed before blaming the airport.
Why has my flight FPS fallen to 10?
A sustained 10 FPS is severe low frame rate: each frame takes about 100 milliseconds, so controls, camera movement and instrument updates will feel visibly delayed.
- If the flight starts near 10 FPS, check resolution, render scaling, frame caps, power mode and an aircraft or airport that may exceed the hardware's capacity.
- If FPS falls to 10 only after several hours, restart the simulator and repeat the destination test. Recovery after restarting points towards accumulated memory, traffic or add-on state.
- If GPU utilisation is consistently high, reduce render resolution, texture demand, clouds or other GPU-heavy effects.
- If GPU utilisation is modest but one CPU thread is saturated, reduce terrain or object detail, AI traffic and simulation complexity. Low total CPU utilisation does not rule out a CPU bottleneck.
- If both clocks and FPS fall, address cooling or power throttling rather than continuing to lower scenery settings.
What does “memory resources are getting low” mean?
A low-memory warning means the simulator or operating system is running short of usable RAM, VRAM, virtual memory or another managed resource; it does not necessarily mean the storage drive is full.
On PC, keep the operating-system page file enabled and system-managed unless there is a specific technical reason not to. More physical RAM may reduce paging, but it cannot expand graphics-card VRAM or repair an add-on that continually retains objects. Our explanation of RAM, VRAM and page-file limits provides the deeper distinction.
How should I handle the MSFS 2024 PS5 memory warning?
On PS5 or PS5 Pro, fully closing MSFS 2024 and restarting the console is the first safe response to a “memory resources are getting low” warning.
- Quit rather than suspend. Do not leave the simulator merely paused or suspended; close the game completely so its session resources are released.
- Restart the console. This clears temporary system and graphics allocations that a normal return to the main menu may retain.
- Test stock content. Repeat the flight with a default aircraft, default airport and optional third-party packages disabled. Reduce live traffic and multiplayer objects for the test.
- Identify a reproducible trigger. If the warning returns at the same airport or after using the same aircraft, record those details. A repeatable stock-content failure after a clean restart points to a simulator issue rather than an add-on.
PS5 owners cannot adjust a Windows page file, install more console RAM or manage VRAM manually. Do not delete saved data or rebuild console storage merely because of one memory warning; those actions can remove settings without fixing a resource leak.
Microsoft Flight Simulator 2024 is the version released for PS5 and PS5 Pro on 8 December 2025. Microsoft Flight Simulator 2020 was never released on PlayStation, so PC-only MSFS 2020 memory instructions do not apply to a PS5 installation.
What if performance mode is temporarily disabled due to high operating temperature?
A “performance mode temporarily disabled due to high operating temperature” message should be treated as a thermal warning, not as a memory or scenery-setting problem.
Save if possible, close the simulator and shut the system down long enough to cool. Make sure external vents are free of dust, the console or computer is not enclosed in a cabinet and warm exhaust air cannot circulate straight back into the intake. If the warning returns soon after a cold start, stop repeated testing and have the cooling or hardware fault assessed.
Will more RAM or restarting fix long-flight FPS loss?
Restarting is an excellent diagnostic and a valid short-term workaround, but more RAM helps only when physical-memory pressure and paging are the actual bottleneck.
A restart clears accumulated scenery, traffic and add-on state. If every long flight slows again, find the component causing that accumulation rather than scheduling routine restarts. Extra RAM will not fix full VRAM, a saturated main thread, thermal throttling or an inefficient airport.
Which causes differ between simulators?
Every simulator can suffer resource pressure, but the workload most likely to accumulate differs by engine and add-on system.
| Simulator | Long-session checks to prioritise |
|---|---|
| Microsoft Flight Simulator 2020 and 2024 | Streamed scenery, detailed destination airports, live traffic, glass cockpits, Community packages, rolling-cache behaviour and memory pressure |
| X-Plane | Plugins, AI aircraft, custom scenery, orthophoto loading, weather tools and VRAM use |
| FSX | Main-thread load, AI traffic, autogen, complex gauges and the 32-bit application's limited address space |
| Prepar3D | Version-dependent memory behaviour, AI traffic, weather, scenery and aircraft or gauge add-ons |
For Microsoft Flight Simulator, our deeper MSFS long-flight checklist covers streamed scenery, aircraft systems and destination-specific tests without applying PC-only fixes to consoles.
Does this advice apply to Workers & Resources low FPS?
Workers & Resources: Soviet Republic is not a flight simulator, but the same CPU-versus-GPU test still helps when that game develops low FPS.
If a new or small map runs well while a developed save does not, vehicle movement, routing and the wider economic simulation are more likely than a graphics fault. Compare performance while the simulation is paused, reduce demanding visual settings only when the GPU is fully occupied, and investigate simulation load when FPS remains low despite modest GPU use. Flight-simulator scenery and aircraft add-on fixes do not otherwise transfer directly.