Why do MSFS add-ons reduce FPS, and how do I fix it?

Microsoft Flight Simulator (MSFS) add-ons reduce FPS when aircraft systems, scenery, traffic or textures overload the CPU main thread, GPU, VRAM or system memory. Fix this by reproducing the slowdown, testing without third-party content, restoring packages in batches, then reducing or removing the add-on that consumes the saturated resource.

Where add-on FPS goes

The slowest part of each frame sets the final frame rate, so a powerful GPU cannot compensate for an aircraft, airport or traffic package that has saturated the CPU main thread.

• Main-thread time: Aircraft systems, glass displays, AI traffic, airport vehicles, animations and large numbers of scenery objects all require CPU work.
• GPU time: Detailed geometry, clouds, lighting, shadows, reflections and transparent surfaces increase rendering time.
• VRAM: High-resolution liveries, airport textures, cockpit displays and render targets can exceed the graphics card’s practical memory budget.
• System memory: Large aircraft, scenery packages, traffic models and long sessions can push RAM and the Windows page file, or unified memory on a console, into pressure.
• Storage and streaming: Slow asset delivery, streamed scenery, damaged cache data and packages installed on slow storage tend to cause hitches rather than a steady FPS loss.

Add-on workloads also combine. A systems-heavy airliner may run acceptably away from cities, and a detailed airport may run well in a default aircraft, yet the two can stutter badly when traffic, terminal interiors and nearby scenery become active during the same approach.

A large Community folder does not automatically mean low in-flight FPS. Regional scenery outside the area may only affect indexing or loading time, while aircraft utilities, traffic injectors and global scripts can remain active throughout a flight.

Which MSFS add-ons hit performance hardest?

Complex aircraft, detailed airports and high-density traffic usually have the greatest FPS impact, but download size alone is a poor measure of performance cost.

Simple sound replacements, efficient liveries and small object packages may have no measurable effect. Conversely, a small utility can be expensive if it repeatedly polls the simulator, spawns many objects or conflicts with another package.

How do I find the add-on causing low FPS?

A repeatable clean-baseline test followed by a binary search is the fastest reliable way to identify a slow add-on or combination of add-ons.

1. Build a repeatable test. Use the same aircraft, runway or parking position, cockpit view, weather preset, time and traffic conditions. Allow scenery and cockpit displays to finish loading before comparing results.
2. Record the symptom. Note whether the problem is steady low FPS, irregular stutters, a gradual long-flight decline or a sudden memory warning. These are not interchangeable faults.
3. Check the limiting resource on PC. The simulator’s developer performance display can distinguish a MainThread limit from a GPU limit. Compare frame times as well as FPS; a stable average can hide disruptive spikes.
4. Establish a clean baseline. Close Microsoft Flight Simulator and move third-party package folders out of Community to a temporary location. Do not modify the simulator’s official package folder.
5. Disable content installed elsewhere. An empty Community folder does not disable Marketplace or other content managed through the simulator’s library. Disable or uninstall removable third-party packages there as well.
6. Repeat the identical flight. If performance recovers, an add-on or interaction is responsible. If it does not, examine the base aircraft, simulator settings, streamed scenery, driver state and thermal behaviour instead.
7. Restore packages in halves. Return half the disabled content, restart the simulator and retest. Keep dividing the failing group until the culprit is isolated. Preserve any required dependencies while testing.
8. Test combinations. Run the suspected package alone, then add the aircraft, traffic and overlapping scenery back one category at a time. Two healthy packages can exceed the available resource budget when used together.
9. Apply the package-specific fix. Update incompatible content, remove duplicate airports, select lower-resolution textures, disable optional interiors or static aircraft, or reduce the add-on’s own density controls.

Change only one variable per comparison. Altering the aircraft, weather, traffic, graphics preset and add-on set together may improve FPS, but it will not reveal which change fixed it.

How should PC users measure the bottleneck?

PC users should compare CPU and GPU frame time, dedicated GPU memory and system memory while reproducing the same scene.

A MainThread indication points towards aircraft systems, traffic, airport activity and object density. Lowering render resolution will do little when the GPU has spare capacity; our main-thread troubleshooting for MSFS 2024 explains which CPU-heavy settings are worth changing.

A GPU limit normally responds to lower render scaling, clouds, shadows, reflections or other graphics-heavy options. Memory usage needs more care: seeing most VRAM allocated is not proof of failure by itself. Warnings, texture eviction and worsening frame-time spikes are stronger evidence of genuine memory pressure.

How do I test add-ons on Xbox or PlayStation?

Console users must isolate removable packages through the simulator’s installed-content interface because Xbox and PlayStation do not expose a PC-style Community folder.

Fully close the simulator after changing content, restart it, then reproduce the same flight. MSFS 2020 is available on PC and Xbox only; MSFS 2024 also runs on PS5 and PS5 Pro as well as PC and Xbox Series X|S.

Consoles provide fewer graphics and diagnostic controls, so use clear A/B comparisons: default versus add-on aircraft, default versus add-on airport, and traffic enabled versus disabled. Adding storage capacity will not increase the console’s working memory.

What does “memory resources are getting low” mean in MSFS 2024?

The “memory resources are getting low” warning means Microsoft Flight Simulator 2024 is struggling to allocate enough working memory for the active aircraft, scenery, textures and simulator processes; it does not identify which package is responsible.

On PC, the pressure may involve dedicated VRAM, system RAM or the page file. A GPU memory warning is more specifically associated with graphics allocations, but VRAM overflow can spill into shared system memory and produce severe stutters before a crash or visible texture problem occurs.

Use this order rather than lowering every setting at once:

1. Restart the simulator. This releases accumulated allocations and shows whether the warning depends on session length.
2. Repeat the scene without third-party content. Start with the aircraft, destination airport, traffic models and high-resolution liveries used when the warning appeared.
3. Remove duplicates. Two versions of the same airport or overlapping city packages may load competing assets.
4. Choose lighter add-on options. Prefer 2K or 4K textures over 8K where offered, and disable optional terminal interiors, static aircraft or detailed cabin models.
5. Reduce memory-heavy graphics settings. Texture resolution is the first candidate for VRAM pressure; render resolution, Terrain Level of Detail and Object Level of Detail can also affect the total memory footprint.
6. Protect system memory on PC. Close memory-heavy background applications, keep free space on the page-file drive and do not disable the Windows page file as a supposed optimisation.

What should Xbox and PS5 users do about the low-memory warning?

On Xbox or PS5, a low-memory warning must be addressed by reducing active content because console memory and graphics memory are system-managed and cannot be upgraded separately.

Fully quit MSFS rather than resuming a suspended session, restart the console, then test with a default aircraft and airport. If that works, restore the add-on aircraft, scenery and traffic separately. Uninstalling unused optional packages can prevent conflicting content from loading, but deleting unrelated saved data or reinstalling the entire simulator is not a dependable memory fix.

If “memory resources are getting low” returns after a fresh restart with default content in the same location, the add-on may not be the cause. A base scenery, aircraft or simulator defect can produce the same message.

How much VRAM does an MSFS 2024 add-on need?

No single VRAM figure can be assigned to an MSFS 2024 add-on because its demand changes with texture option, display resolution, aircraft, airport, weather and every other asset visible in the scene.

Judge the combined workload rather than the package in isolation. High VRAM allocation without stutters can be normal caching behaviour; repeated warnings, abrupt FPS collapse, texture replacement and recovery after removing a livery or airport are more useful evidence.

Why does MSFS 2024 stutter even when average FPS looks acceptable?

MSFS 2024 stutters when individual frames take much longer than the surrounding frames, commonly because an add-on is loading assets, compiling work, spawning traffic or forcing memory to be moved.

Storage and streaming hitches need different treatment from steady low FPS. Keep large packages on fast local storage, check that symbolic links or package managers are not pointing to an unavailable drive, and test rolling-cache behaviour where the simulator offers that feature. For MSFS 2020 specifically, our micro-pause and scenery-streaming checks cover the version-specific causes.

Why does MSFS 2024 stutter on landing?

Stutters on landing usually occur because the simulator must activate detailed airport scenery, ground traffic, AI aircraft and cockpit systems while loading the arrival area.

Test the destination with a default aircraft and no traffic, then restore the aircraft, traffic and airport separately. If each performs well alone, reduce the combination rather than blaming one package. Our landing-area FPS diagnostic sequence covers this combined-load case without requiring every global graphics setting to be lowered.

Why does FPS fall after a long flight?

A decline that builds over several hours and resets after restarting MSFS points towards memory growth, accumulated traffic, aircraft scripts or cache behaviour rather than an airport that is simply demanding from the start.

Repeat the route without the aircraft, traffic and destination packages, but change one category at a time. The long-flight performance isolation process explains how to separate memory accumulation from a demanding arrival area.

Why is MSFS 2024 Frame Generation not working?

MSFS 2024 Frame Generation may be unavailable because the PC hardware, graphics driver, Windows configuration or selected rendering mode does not support that implementation; when enabled, it still cannot repair native frame-time spikes or memory exhaustion.

If the option is missing or greyed out, check the following:

1. Confirm hardware support. Frame-generation implementations are tied to supported GPU features; an upscaling option with a similar name does not guarantee frame-generation support.
2. Check software prerequisites. Install a suitable graphics driver and enable any Windows feature required by the GPU implementation, including Hardware-accelerated GPU scheduling where specified.
3. Use a supported graphics combination. The selected rendering API, anti-aliasing or upscaling mode must be compatible with the frame-generation option. Restart MSFS after changing renderer-level settings.
4. Remove conflicting hooks. Temporarily disable overlays, frame limiters and monitoring tools one at a time if the setting enables but does not behave correctly.
5. Test without add-ons. Use a default aircraft and airport to establish a stable native frame rate before reintroducing the content that caused low FPS.

If the displayed FPS rises but the flight still stutters, Frame Generation is working but the underlying frames remain uneven. It inserts generated frames between rendered ones; it does not make the main thread finish aircraft calculations sooner, prevent scenery-loading hitches or free VRAM. Different counters may also report rendered and displayed frames differently.

Turn Frame Generation off while comparing add-ons, or keep it in exactly the same state for every run. The PC troubleshooting above does not apply to Xbox or PlayStation output modes, which are managed by the simulator and console.

How can I make MSFS run smoother without removing every add-on?

The best way to make MSFS run smoother is to reduce the setting or optional feature that consumes the resource already at its limit.

Use an add-on’s own controls before reducing global simulator quality. Disabling an airport’s terminal interiors, animated passengers, static aircraft or ultra-resolution textures usually preserves more visual quality than lowering every airport and aircraft in the simulator.

Do load order, rolling cache or reinstalling fix add-on FPS?

Load-order changes, cache resets and reinstalls only help when the underlying problem is a conflict, damaged data or incorrect package priority; they cannot make an inherently demanding add-on inexpensive.

• Load order: Change priority when two packages replace the same airport, terrain or navigation data. Priority decides which asset wins, but it does not guarantee that all duplicate workload disappears.
• Rolling cache: Clear or recreate it when streamed scenery is corrupted or produces location-specific pauses. It rarely fixes steady low FPS caused by aircraft systems or AI traffic.
• Reinstallation: Reinstall a package after confirming missing, altered or incomplete files. Reinstalling the same healthy textures, objects and scripts will not reduce their performance cost.
• Deleting caches indiscriminately: Avoid treating every cache as disposable. The next flight may stutter while data is rebuilt, making the add-on appear worse.

Keep the add-on when its distinctive features justify a manageable cost and it provides effective detail controls. Replace or remove it when a clean baseline restores performance, conflicts and duplicates have been ruled out, and no package option reduces the resource that is actually saturated.