Shader Compilation Stutter Explained (and How to Reduce It)

Shader compilation stutter is a hitch that happens when a game has to prepare a new shader for your graphics card in the middle of play. It shows up the first time you see something new and then fades, which makes it easy to recognise once you know the pattern.

This guide explains what shaders are, why compiling them causes stutter, and the settings that reduce it. Stutter has other causes too; our complete guide to fixing stuttering in PC games covers them all, and the wider PC game troubleshooting guide covers crashes and errors.

What are shaders, and why do they compile?

A shader is a small program that runs on the graphics card and decides how something is drawn: the colour of a surface, how light falls on it, how smoke or water moves. A modern game uses thousands of them.

Games ship shaders in an intermediate form. Before the GPU can run one, the graphics driver has to compile it into instructions for your exact card and driver version. That step takes a few milliseconds to much longer per shader, depending on its complexity and on the CPU.

In Direct3D 12, Microsoft’s documentation describes how most of the graphics pipeline, including the shaders that will be used, is set through pipeline state objects, which the game creates before drawing with them. Creating one can include compiling the shaders it uses. Games built on Vulkan follow a similar model.

Why does compiling cause stutter?

At 60 FPS, the game has about 16.7ms to produce each frame. At 144 FPS, it has about 6.9ms.

If the game needs a shader that hasn’t been compiled yet, it has to wait for the compile before it can draw that frame. A compile that takes 50ms or 100ms turns one frame into a visible freeze, even though every frame around it was on time.

That is why the pattern is so distinctive:

If your hitches don’t follow this pattern, the cause is probably something else, such as running out of video memory or a slow drive.

Pre-compilation screens

Many games now compile shaders before you play. You see a “Compiling shaders”, “Optimizing shaders” or “Preparing” message at the main menu, sometimes with a progress bar.

• Let it finish. Starting a game before the bar reaches 100 percent means the rest compile during play.
• Expect it after updates. A new graphics driver or a game patch can trigger the whole step again. That’s normal.
• Expect it to take a while. On a large game it can take several minutes, longer on CPUs with fewer cores.

Some games only pre-compile part of their shaders, so some hitching can remain even after the step finishes.

Shader cache settings in the graphics driver

The graphics driver keeps compiled shaders in a shader cache on your drive, so it doesn’t have to compile them again next time. Make sure the cache is working.

• NVIDIA: in the NVIDIA Control Panel, open Manage 3D settings and check Shader Cache Size. Leave it on Driver Default or a larger size, not Disabled.
• AMD: in AMD Software, the shader cache setting is in the graphics settings. Leave it enabled. The Reset Shader Cache option is there for troubleshooting.
• Intel Arc: the driver manages the cache automatically.

Keep some free space on the drive that holds Windows, since the caches are stored there by default.

Steam also has a Shader Pre-Caching option under Steam → Settings → Downloads. When it is on, Steam can download shaders other players with the same hardware have already compiled for supported games. Leave it on unless you are short of disk space.

Why it gets better after a while

Every shader only has to be compiled once per driver version. The first time through a level, each new effect costs a hitch. On the second run, the shaders come from the cache and the same level plays smoothly.

That is also why judging a game’s smoothness in the first ten minutes can be misleading. Play the same area twice before deciding that your settings are wrong.

What else reduces shader stutter

1. Install the game on an SSD. Reading cached shaders and the files they belong to is faster.
2. Keep the graphics driver current, but not on every release. Each driver update means rebuilding the cache, so update when there’s a reason.
3. Close CPU-heavy background apps. Compilation competes with them for processor time.
4. Check for game patches. Developers often improve pre-compilation in updates when players report stutter.
5. Don’t clear the cache without a reason. It only makes the next session worse.

If a game still hitches after all of this on a healthy system, the remaining stutter is in how the game handles shaders, and only a patch from the developer can fix it.