Shader Cache Explained

Estimated Lesson Time: 30–40 Minutes

Lesson Overview

Throughout this module, we’ve focused on optimising your graphics drivers and understanding how the GPU processes Microsoft Flight Simulator.

In this lesson, we’re going to explore one of the most misunderstood parts of PC gaming:

Shader Cache.

You’ve probably seen advice online telling you to clear your shader cache whenever your simulator stutters.

Sometimes that’s good advice.

Sometimes it’s completely unnecessary.

To understand why, we first need to understand what shaders actually are and why your graphics card compiles them.

By the end of this lesson, you’ll know when clearing your shader cache can solve problems, when you should leave it alone, and why rebuilding the cache is a normal part of the optimisation process.

Lesson Objectives

By the end of this lesson you will understand:

What shaders are.

Why shaders must be compiled.

What Shader Cache does.

Where Shader Cache is stored.

Why shader stutters occur.

When to clear Shader Cache.

How Windows Shader Cache differs from NVIDIA Shader Cache.

Why shader compilation after updates is completely normal.

1. What Are Shaders?

A shader is a small program that tells your graphics card how to render part of an image.

Every frame in Microsoft Flight Simulator uses thousands of shader calculations.

Examples include:

• Clouds.
• Water.
• Reflections.
• Cockpit displays.
• Lighting.
• Shadows.
• Terrain.
• Buildings.
• Glass.
• Weather effects.

Without shaders, your GPU wouldn’t know how these objects should appear.

Think of shaders as instructions that tell the graphics card exactly how every surface should be drawn.

2. What Is Shader Compilation?

Before your GPU can use a shader, it often needs to compile it.

Compilation converts the shader into a form that your graphics card can execute efficiently.

The first time the simulator encounters a new shader, this process may take a small amount of time.

If the shader has never been compiled before, you may notice:

• A brief pause.
• A hitch.
• A small stutter.

Once compiled, the shader can usually be reused.

This is why many stutters disappear after flying the same aircraft or route multiple times.

3. What Is Shader Cache?

Shader Cache is a storage area where compiled shaders are saved.

Instead of compiling the same shader every time you launch Microsoft Flight Simulator, your PC simply loads the compiled version from storage.

Benefits include:

• Faster loading.
• Fewer compilation stutters.
• More consistent performance.
• Reduced CPU overhead during repeat flights.

Shader Cache doesn’t increase your average FPS.

Instead, it helps improve frame consistency and smoothness.

4. Where Is Shader Cache Stored?

Shader caches can exist in more than one place.

NVIDIA Shader Cache

Managed by the graphics driver.

Stores compiled GPU shaders used by supported applications.

Windows DirectX Shader Cache

Managed by Windows.

Stores DirectX shader data for supported applications.

Game-Specific Shader Data

Some games maintain their own shader-related data in addition to the operating system and graphics driver caches.

Microsoft Flight Simulator may rebuild shader-related data after significant updates.

5. Why Do Shader Stutters Happen?

Shader stutters usually occur when the GPU encounters a shader that hasn’t yet been compiled.

This commonly happens:

• After installing a new graphics driver.
• After a major simulator update.
• After deleting shader caches.
• The first time flying in a new location.
• When loading a new aircraft.
• When introducing new add-ons.

These stutters are usually temporary.

As more shaders are compiled and cached, performance often becomes more consistent.

6. When Should You Clear Shader Cache?

Clearing Shader Cache can be useful when:

• A graphics driver becomes corrupted.
• You experience unusual graphical glitches.
• You’ve performed a clean graphics driver installation.
• A major simulator update causes persistent rendering issues.
• You’re troubleshooting unexplained graphical problems.

It is not something that should be done routinely.

7. What Happens After Clearing Shader Cache?

When you delete the Shader Cache:

The simulator loses its library of previously compiled shaders.

The next time you launch Microsoft Flight Simulator:

• Shaders must be compiled again.
• Initial flights may contain temporary stutters.
• Loading times may increase slightly.

This is expected behaviour.

As the cache rebuilds, performance usually becomes smoother again.

8. Windows DirectX Shader Cache

Windows stores compiled DirectX shaders separately from the NVIDIA driver.

You can review this cache through Windows Storage settings under Temporary Files.

If you’re troubleshooting graphics issues, clearing the DirectX Shader Cache may help.

Just remember that Windows will rebuild it automatically during future gameplay.

9. Shader Cache and Driver Updates

Installing a new graphics driver often changes how shaders are processed.

As a result, existing shader caches may no longer be suitable.

The driver or Windows may rebuild them automatically.

Because of this, it’s normal to experience:

• Slightly longer loading.
• Minor shader compilation stutters.
• Temporary inconsistency.

These effects usually disappear after a few flights.

10. Common Myths

Myth 1

“Clearing Shader Cache increases FPS.”

False.

Shader Cache mainly improves smoothness and reduces repeated compilation.

Average FPS usually changes very little.

Myth 2

“You should clear Shader Cache every week.”

False.

Only clear it when troubleshooting or after significant driver-related changes.

Myth 3

“Shader stutters mean your PC is too slow.”

False.

Shader compilation is a normal part of modern graphics rendering.

Myth 4

“If I clear the cache, my simulator is permanently faster.”

False.

Initially, performance may actually feel worse while the cache rebuilds.

Myth 5

“Shader Cache is the same as Rolling Cache.”

False.

Rolling Cache stores streamed scenery.

Shader Cache stores compiled graphics instructions.

They serve completely different purposes.

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