Advanced Add-on Optimisation
Estimated Lesson Time: 60–70 Minutes
Lesson Overview
By this point in the Performance Academy, you’ve learned how to optimise your PC, configure Microsoft Flight Simulator, benchmark your system and organise your Community Folder.
Now it’s time to optimise something that almost every serious Flight Simulator user relies on:
Third-party add-ons.
Modern Flight Simulator can be transformed with high-quality airports, advanced aircraft, realistic traffic, ground handling, ATC enhancements and navigation tools.
These add-ons create an incredibly immersive experience—but they also introduce additional workload.
Some primarily affect the CPU.
Others increase GPU usage.
Some consume VRAM.
Others have little measurable performance impact.
The goal of this lesson is to teach you how to optimise your entire add-on environment without sacrificing the realism that makes Microsoft Flight Simulator so enjoyable.
Lesson Objectives
By the end of this lesson you will understand:
How third-party add-ons affect performance.
How to optimise popular utilities.
How to balance realism with smooth performance.
How to identify poorly optimised add-ons.
How to resolve scenery conflicts.
How to optimise AI traffic.
How to maintain compatibility after simulator updates.
How to troubleshoot add-on related performance problems.
Why Add-on Optimisation Matters
Every add-on asks your computer to do additional work.
This may include:
- Rendering more objects.
- Simulating more aircraft.
- Managing more AI.
- Loading larger textures.
- Running additional background processes.
- Streaming more scenery.
The more add-ons you install, the more important optimisation becomes.
Good optimisation is about achieving the highest level of realism your hardware can comfortably support.
Optimising Third-Party Airports
High-quality airports are often the most demanding add-ons in the simulator.
They commonly include:
- High-resolution textures.
- Detailed terminals.
- Animated jetways.
- Interior modelling.
- Dynamic lighting.
- Custom objects.
- Static aircraft.
- Service vehicles.
CPU Impact
Moderate to High.
The CPU processes:
- Object placement.
- Animations.
- Airport logic.
- Ground traffic.
GPU Impact
High.
The GPU renders:
- Thousands of additional objects.
- Detailed textures.
- Glass reflections.
- Lighting.
- Shadows.
Optimisation Tips
Reduce unnecessary airport clutter if configurable.
Disable duplicate airports.
Keep airport packages updated.
Choose realistic graphics settings based on your hardware.
GSX Optimisation
GSX provides realistic:
- Passenger boarding.
- Catering.
- Fuel services.
- Pushback.
- Ground vehicles.
- Baggage handling.
CPU Impact
Moderate.
Every moving vehicle and animated passenger requires processing.
Optimisation
Avoid excessive simultaneous services.
Keep GSX updated.
Benchmark with and without GSX to understand its impact on your system.
FSLTL Optimisation
FSLTL dramatically increases immersion through live AI traffic.
However, AI traffic is one of the largest CPU workloads in Microsoft Flight Simulator.
CPU Impact
High.
The CPU manages:
- Aircraft movement.
- Taxi logic.
- Flight planning.
- Lighting.
- Navigation.
- Collision avoidance.
GPU Impact
Moderate.
Every aircraft must also be rendered.
Optimisation Tips
Adjust AI traffic density to match your hardware.
Remember that more traffic isn’t always better if it causes unstable frame times.
Finding the right balance often produces a smoother experience than simply increasing aircraft numbers.
BeyondATC Optimisation
BeyondATC introduces realistic ATC interaction and traffic management.
CPU Impact
Moderate.
The application processes communications and aircraft interactions.
Optimisation Tips
Ensure BeyondATC is running the latest version.
Benchmark with and without it if troubleshooting performance.
Navigraph Performance
Navigraph primarily provides:
- Navigation databases.
- Charts.
- Flight planning integration.
Performance Impact
Generally Low.
The navigation database itself has almost no measurable FPS impact.
Companion applications may consume a small amount of RAM and CPU resources, but this is usually modest.
Toolbar Pushback
Toolbar Pushback replaces the default pushback system with additional functionality.
CPU Impact
Very Low.
GPU Impact
Negligible.
For most users, there is no measurable FPS difference.
AutoFPS Configuration
AutoFPS dynamically adjusts simulator settings to maintain smooth performance.
Examples include:
- Terrain LOD.
- Object LOD.
- Traffic.
Benefits
Maintains more consistent frame rates during demanding situations.
Important
When benchmarking, disable AutoFPS unless you’re specifically measuring its effectiveness.
Dynamic adjustments make benchmark comparisons unreliable because the settings are constantly changing.
AI Traffic Balancing
One of the biggest mistakes users make is setting AI traffic as high as possible.
Higher traffic means:
More aircraft.
More taxi calculations.
More lighting.
More animations.
More CPU workload.
Instead of chasing maximum realism, aim for the highest traffic level your system can handle while maintaining stable frame pacing.
Airport Object Optimisation
Many airports include:
- Static aircraft.
- Ground vehicles.
- Baggage carts.
- Passenger buses.
- Service equipment.
These objects increase both CPU and GPU workload.
If your preferred scenery allows optional object density settings, consider reducing non-essential clutter while preserving the overall look of the airport.
LOD Management With Add-ons
High-detail scenery often benefits from sensible LOD settings.
Extremely high Terrain LOD combined with detailed airports and AI traffic can quickly overwhelm the CPU.
Similarly, very high Object LOD increases the number of scenery objects rendered over long distances.
Adjust these settings in balance with the complexity of your installed add-ons rather than assuming the highest values are always best.
Airport Conflicts
Conflicts occur when multiple packages modify the same location.
Symptoms include:
- Missing buildings.
- Floating objects.
- Duplicate jetways.
- Broken taxiways.
- Terrain issues.
Always verify that only one active version of an airport is installed.
Duplicate Scenery
Duplicate scenery is a surprisingly common issue.
Examples include:
Marketplace version installed.
↓
Community version installed.
↓
Both active.
The simulator now attempts to load two versions of the same airport.
Always remove or disable duplicate scenery packages.
Marketplace vs Community Versions
Many airports are available through both the Marketplace and independent developers.
Running both versions simultaneously often causes conflicts.
Choose one version and keep it updated.
If migrating from Marketplace to Community (or vice versa), uninstall the previous version first.
Sim Update Compatibility
Every major Sim Update has the potential to affect third-party add-ons.
After each update:
Check for:
- Airport updates.
- Aircraft updates.
- Utility updates.
- Library updates.
Running outdated packages alongside a new simulator version can lead to compatibility issues and unexpected behaviour.
Identifying Poorly Optimised Add-ons
Not every add-on is built to the same standard.
Signs of a poorly optimised add-on may include:
- Significant FPS drops compared with similar products.
- Excessive VRAM usage.
- Long loading times.
- Stuttering isolated to one package.
- Repeated crashes.
Always benchmark before assuming an add-on is poorly optimised.
Use the same test flight and compare it against your baseline.
Safely Removing Problematic Add-ons
If an add-on appears to be causing issues:
- Disable it rather than deleting it immediately.
- Restart the simulator.
- Repeat your benchmark.
- Compare the results.
If the issue disappears, you’ve identified the likely cause.
This methodical approach prevents unnecessary reinstalls and makes troubleshooting much faster.
Building an Optimised Add-on Environment
A well-balanced simulator isn’t the one with the largest number of add-ons.
It’s the one where every installed add-on has a purpose.
Ask yourself:
- Do I actually use this airport?
- Do I need this utility every flight?
- Is this scenery duplicated?
- Is this livery package worth the additional storage?
Removing unused content simplifies maintenance and reduces the likelihood of conflicts.
Common Mistakes
Installing every available add-on.
Enabling maximum AI traffic regardless of hardware.
Running duplicate airport packages.
Forgetting to update utilities after a Sim Update.
Leaving AutoFPS enabled during controlled benchmarks.
Deleting add-ons before testing them individually.
Assuming every performance problem is caused by Microsoft Flight Simulator itself.
Student Exercise
Today you’re going to optimise your installed add-ons.
Step 1
Review every major add-on currently installed.
Identify:
- Airports.
- Utilities.
- AI traffic.
- Navigation tools.
- Ground handling software.
Step 2
Check for:
- Duplicate airports.
- Duplicate scenery.
- Outdated packages.
- Inactive utilities.
- Sim Update compatibility.
Step 3
Run your permanent benchmark flight.
Record:
- Average FPS.
- 1% Lows.
- MainThread Status.
- GPU Utilisation.
- VRAM Usage.
- Overall smoothness.
Step 4
Optimise one category at a time.
For example:
- Adjust AI traffic density.
- Disable duplicate scenery.
- Reduce unnecessary airport clutter.
- Temporarily disable one utility.
Repeat the benchmark after each change.
Step 5
Compare your results.
Ask yourself:
- Which optimisation produced the biggest improvement?
- Which add-on had the largest CPU impact?
- Which add-on increased GPU workload the most?
- Did any optimisation improve frame pacing more than FPS?
- Which settings provided the best balance between realism and performance?
Update your Performance Profile with your findings.
Student Checklist
Installed add-ons reviewed.
Duplicate scenery removed.
AI traffic optimised.
Utilities checked.
Compatibility verified.
Benchmark completed.
Results compared.
Performance Profile updated.
Lesson Summary
Congratulations.
You now understand how to optimise a modern Microsoft Flight Simulator installation with multiple third-party add-ons.
Remember:
- Every add-on contributes additional workload, but the type of workload varies depending on what the add-on does.
- High-detail airports and AI traffic often have the greatest impact on performance, while utilities such as navigation tools generally have a much smaller effect.
- A balanced simulator is achieved by carefully selecting and configuring add-ons rather than simply installing as many as possible.
- Benchmarking before and after each change allows you to identify the true impact of every optimisation.
- A clean, organised and well-maintained add-on environment will provide a smoother, more stable simulator and make future troubleshooting significantly easier.
Knowledge Check
- Why do different types of add-ons affect the CPU and GPU in different ways?
- Which add-ons generally have the greatest impact on MainThread performance?
- Why should AI traffic be balanced rather than simply set to the highest possible value?
- What problems can duplicate airport packages cause?
- Why should AutoFPS be disabled during controlled benchmarks?
- How can Sim Updates affect third-party add-ons?
- What is the safest method for identifying a problematic add-on?
- Based on your own benchmarks, which optimisation produced the greatest improvement, and why do you think it was effective?