It's the shader cache
You updated your Nvidia driver, booted Fortnite, and now it stutters every time you hit a new area or use a weapon. Same thing happened to me on a 4070 Ti Super with driver 561.09. The fix isn't reinstalling the driver or rolling back. It's capping the shader cache size.
The fix
- Open Nvidia Control Panel (right-click desktop → Nvidia Control Panel).
- Go to Manage 3D Settings → Program Settings → add FortniteClient-Win64-Shipping.exe.
- Find Shader Cache Size and set it to 10 GB (not Unlimited).
- Set Low Latency Mode to On (not Ultra).
- Click Apply, then reboot.
That's it. Launch Fortnite, play a match. The stutter should be gone after the first few seconds of shader compilation.
Why this works
What's actually happening here is that Nvidia changed how the shader cache behaves starting in driver 560. Before 560, the cache was capped at a few hundred MB. Starting with 560, Nvidia pushed the default to Unlimited. Sounds good in theory — more cached shaders, less recompilation. But here's the catch: when the cache is Unlimited, the driver doesn't evict old shaders. It keeps every shader from every game you've ever run since the driver was installed. For Fortnite, which compiles a massive number of DX12 shaders (thousands per level), the cache grows to 20–30 GB. That's fine for performance. The problem is when the cache rebuilds.
Every driver update invalidates the existing shader cache. Driver 560+ marks the whole thing as stale. When you launch Fortnite after a driver update, it starts compiling shaders from scratch. With Unlimited cache, the driver doesn't know where to stop — it tries to store every single shader variant for every possible rendering path. That causes hitches while the driver writes new cache entries to disk and the game waits for shaders to compile.
By capping the cache at 10 GB, you force the driver to manage space properly. It evicts old shaders from other games and only keeps the most recent ones. Fortnite still compiles shaders, but the cache stays small enough that disk writes don't cause stutter. The 10 GB limit is a sweet spot: enough for Fortnite's shaders plus a couple of other games, small enough that a full rebuild takes 5 seconds instead of 30.
Low Latency Mode at On (not Ultra) helps too. Ultra forces the GPU to wait for the CPU, which can actually increase stutter if the CPU is compiling shaders. On lets the GPU run ahead a little, smoothing out those compilation hitches.
Less common variations
If the above doesn't fix it entirely, check these:
- Windows Game Mode: Turn it off. Windows 11 24H2 has a bug where Game Mode overrides Nvidia's shader cache settings. Go to Settings → Gaming → Game Mode → Off. Reboot.
- DirectX version: Fortnite defaults to DX12 on modern hardware. If you're on DX11, switch to DX12 in Fortnite's video settings. DX12's shader compilation is more efficient, and the Nvidia cache works better with it. The stutter you see on DX11 is often CPU-side, not cache-related.
- Multiple GPUs: If you're on a laptop with an iGPU and dGPU, make sure Fortnite runs on the Nvidia card. In Windows Graphics Settings, set FortniteClient-Win64-Shipping.exe to High Performance. The iGPU can't handle shader compilation the same way and causes stutter.
- Shader Cache Location: Some users with small SSDs (256 GB or less) see stutter because the cache fills up the drive. Check C:\ProgramData\NVIDIA Corporation\NvCache. Delete everything in there (safe to do, Nvidia will rebuild it). Then set the cache cap.
Prevention
Once you've fixed it, don't touch the settings again. Every time you update your Nvidia driver, the cache will rebuild — but as long as the cap is 10 GB, it'll rebuild fast and you won't notice. If you're the type who updates drivers the day they drop, wait a week. Nvidia's Game Ready drivers often have shader cache bugs in the first release. The 560.94 hotfix resolved some of these issues.
Also, don't run disk cleanup tools that wipe the shader cache. Windows Disk Cleanup will delete the NvCache folder if you check the "Delivery Optimization Files" box. That forces a full rebuild the next time you play. Just leave it alone.
One last thing: if you're overclocking your GPU memory, drop it by 100 MHz. Fortnite's DX12 shader compilation is sensitive to memory errors. An unstable memory clock can cause shader corruption that manifests as stutter. Not every game shows this, but Fortnite does. Drop the memory clock, run the game for 10 minutes, and see if it's smoother. If it is, your OC was the problem all along.