Glass Cockpit Refresh Rate Explained
Estimated Lesson Time: 40–50 Minutes
Lesson Overview
Throughout this course, we’ve learnt that some graphics settings primarily affect the GPU, while others place more demand on the CPU.
Today we’re going to look at one of the most important CPU-related settings in Microsoft Flight Simulator:
Glass Cockpit Refresh Rate.
This setting is often overlooked, yet it can have a major impact on performance—especially when flying modern airliners and advanced glass cockpit aircraft.
Unlike scenery or graphics settings, Glass Cockpit Refresh Rate doesn’t change how beautiful the world looks.
Instead, it controls how often the aircraft’s digital displays are updated.
Every Primary Flight Display (PFD), Navigation Display (ND), Electronic Flight Bag (EFB), engine display and multifunction display must constantly update.
These screens are not static images.
They are live computer displays running complex systems in real time.
The faster they refresh…
The more work your CPU must perform.
Understanding this setting can significantly improve performance on CPU-limited systems.
Lesson Objectives
By the end of this lesson you will understand:
What Glass Cockpit Refresh Rate is.
Why it affects CPU performance.
Why modern airliners are more demanding.
How different aircraft are affected.
Why complex avionics increase CPU load.
When to reduce Glass Cockpit Refresh Rate.
How to balance cockpit smoothness with simulator performance.
1. What Is Glass Cockpit Refresh Rate?
Traditional aircraft use analogue instruments.
Examples include:
- Airspeed indicator.
- Altimeter.
- Vertical speed indicator.
- Artificial horizon.
These gauges are relatively simple.
Modern aircraft use digital displays instead.
Examples include:
- Primary Flight Display (PFD).
- Navigation Display (ND).
- Engine Indication and Crew Alerting System (EICAS).
- Electronic Centralised Aircraft Monitor (ECAM).
- Multi-Function Display (MFD).
- Electronic Flight Bags (EFBs).
These displays behave like miniature computers.
Glass Cockpit Refresh Rate determines how frequently these displays are updated every second.
Example
Imagine your PFD updating:
Every fraction of a second.
It constantly redraws:
- Airspeed tape.
- Altitude tape.
- Flight Director.
- Autopilot modes.
- Artificial horizon.
- Navigation data.
- Wind.
- Waypoints.
- Terrain.
- Traffic.
Every update requires CPU processing.
2. Why Is It CPU Intensive?
Unlike scenery…
Glass cockpit displays must constantly calculate new information.
Every refresh requires the CPU to process:
Aircraft position.
Altitude.
Speed.
Vertical speed.
Heading.
Navigation.
Flight plan.
Autopilot modes.
Weather radar (where available).
Traffic information.
Terrain data.
Engine instruments.
Warnings.
System pages.
This happens continuously throughout the flight.
The more often the displays refresh…
The more calculations the CPU performs.
Think Of It Like A Television
Imagine watching two televisions.
One updates:
30 times every second.
The other updates:
60 times every second.
The second television provides smoother movement.
However…
It also requires more processing.
Glass Cockpit Refresh Rate works exactly the same way.
3. Glass Cockpit Refresh Settings
Microsoft Flight Simulator allows different refresh rates depending on the aircraft and simulator version.
Typically, you’ll see options such as:
- Low
- Medium
- High
Higher refresh rates make displays appear smoother but require more CPU resources.
Lower refresh rates reduce CPU workload but may make display animations slightly less fluid.
4. PMDG Aircraft
PMDG aircraft feature highly detailed avionics and aircraft systems.
Examples include:
- PMDG 737.
- PMDG 777.
These aircraft simulate:
- Flight Management Computer (FMC).
- Autoflight.
- Electrical systems.
- Hydraulic systems.
- Pressurisation.
- Fuel systems.
- Navigation.
The cockpit displays update constantly as these systems change.
Reducing the Glass Cockpit Refresh Rate can help free CPU resources, particularly at complex airports.
5. Fenix Aircraft
The Fenix A320 is one of the most advanced airliners available for Microsoft Flight Simulator.
Its displays continuously update:
- ECAM pages.
- Navigation Display.
- Primary Flight Display.
- Flight Management Guidance Computer.
- System synoptics.
- Engine parameters.
Combined with the aircraft’s deep systems simulation, this places significant demand on the CPU.
On systems that are already MainThread limited, lowering the Glass Cockpit Refresh Rate may improve smoothness while having only a small effect on usability.
6. iniBuilds Aircraft
Aircraft from iniBuilds, such as the A350, feature advanced avionics and detailed cockpit systems.
Large multifunction displays, navigation systems and extensive aircraft logic increase the amount of information that must be processed every second.
As a result, aircraft with several high-resolution displays can be more CPU demanding than simpler aircraft.
Reducing the refresh rate may provide additional CPU headroom on some systems, particularly during taxi, departure and arrival at large airports.
7. Garmin Avionics
Garmin systems are common in General Aviation aircraft.
Examples include:
- G1000.
- G3000.
- G5000.
These displays continuously update:
- Moving maps.
- Terrain.
- Traffic.
- Navigation.
- Engine instruments.
- Weather overlays (where available).
Although they are generally less demanding than complex airliners, multiple Garmin displays can still place noticeable load on the CPU.
8. Airliners vs General Aviation
Why do airliners often perform worse?
Because they simulate much more than basic flight instruments.
Modern airliners contain:
Multiple displays.
Autopilot computers.
Flight management systems.
Navigation databases.
Electronic checklists.
Weather integration.
Engine monitoring.
Hydraulic logic.
Electrical systems.
Fuel systems.
Pressurisation.
Every one of these systems updates continuously.
This is why airliners generally place much greater demand on the CPU than a simple Cessna.
9. CPU vs GPU Impact
Glass Cockpit Refresh Rate is almost entirely a CPU setting.
The CPU:
Calculates the aircraft systems.
Updates every display.
Processes navigation.
Updates flight management.
Calculates moving maps.
The GPU simply draws the completed image on the screen.
This means lowering Glass Cockpit Refresh Rate usually reduces MainThread workload rather than GPU utilisation.
Performance Summary
|
Feature |
CPU Impact |
GPU Impact |
|---|---|---|
|
Glass Cockpit Refresh |
Very High |
Very Low |
|
Garmin Displays |
High |
Very Low |
|
PMDG Displays |
Very High |
Very Low |
|
Fenix Displays |
Very High |
Very Low |
|
iniBuilds Displays |
Very High |
Very Low |
|
Airliner Avionics |
Very High |
Low |
10. When Should You Increase It?
Use a higher refresh rate if:
- You have a powerful CPU.
- You value the smoothest cockpit displays.
- You are not MainThread limited.
- You mainly fly less demanding aircraft.
- You have spare CPU headroom.
11. When Should You Reduce It?
Reduce Glass Cockpit Refresh Rate if:
- Developer Mode reports Limited by MainThread.
- Performance drops at major airports.
- Taxiing is inconsistent.
- Cockpit displays remain smooth enough at lower refresh rates.
- You fly complex aircraft such as the PMDG 737/777, Fenix A320 or iniBuilds A350 on a CPU-limited system.
Reducing this setting can often improve smoothness with only a small change in the appearance of the displays.
12. Common Myths
Myth 1
“Glass Cockpit Refresh Rate affects my graphics card.”
False.
It primarily increases CPU workload.
Myth 2
“Only Garmin aircraft use Glass Cockpit Refresh.”
False.
Modern airliners also rely heavily on continuously updating digital displays.
Myth 3
“Lower refresh makes my aircraft less realistic.”
False.
It only changes how frequently the displays are updated.
The aircraft systems themselves continue to operate normally.
Myth 4
“This setting only matters in the cockpit.”
False.
The CPU continues updating these systems throughout the entire flight, regardless of where you look.
Student Exercise
Today we’re going to compare Glass Cockpit Refresh Rate.
Step 1
Load your Module 1 benchmark flight.
Use:
- Same airport.
- Same aircraft.
- Same weather.
Choose a complex aircraft with digital cockpit displays.
Step 2
Compare:
- Low.
- Medium.
- High.
Step 3
During each test, record:
- Average FPS.
- Lowest FPS.
- MainThread status.
- CPU utilisation.
- GPU utilisation.
- Cockpit display smoothness.
- Taxi performance.
- Approach performance.
- Overall simulator smoothness.
Step 4
Compare the results.
Ask yourself:
- Did reducing the refresh rate improve MainThread performance?
- Were the cockpit displays still perfectly usable?
- Was the performance gain worth the small reduction in display smoothness?
- Which setting provides the best balance for your aircraft and CPU?
Student Checklist
Glass Cockpit Refresh tested.
CPU utilisation monitored.
MainThread status recorded.
Cockpit display smoothness compared.
Taxi performance evaluated.
Best refresh rate selected.
Lesson Summary
Congratulations.
You now understand one of the most important CPU-related settings in Microsoft Flight Simulator.
Remember:
- Glass Cockpit Refresh Rate controls how frequently digital cockpit displays are updated.
- It primarily affects CPU performance rather than GPU performance.
- Complex aircraft such as the PMDG 737/777, Fenix A320, iniBuilds A350 and Garmin-equipped aircraft all rely on continuously updating avionics.
- Higher refresh rates create smoother display animations but require more CPU processing.
- Lower refresh rates can reduce MainThread workload and improve performance on CPU-limited systems.
- Choosing the right refresh rate is about balancing cockpit smoothness with overall simulator performance.
Knowledge Check
- What does Glass Cockpit Refresh Rate control?
- Why is this setting primarily CPU intensive?
- Why are complex airliners generally more demanding than analogue aircraft?
- Which aircraft types are most affected by this setting?
- What happens when the refresh rate is reduced?
- Why can lowering this setting improve MainThread performance?
- When should you consider reducing Glass Cockpit Refresh Rate?
- Based on your benchmark testing, which refresh rate provided the best balance between cockpit smoothness and simulator performance on your system?