Tuning FastFlag Editor & JSON Import/Export for your Windows hardware
Every Windows PC responds differently to FastFlag Editor & JSON Import/Export. On integrated Intel UHD / Iris Xe or AMD Radeon Vega laptops, conservative settings keep GPU load under 90% and prevent thermal throttling.
On dedicated NVIDIA GeForce GTX/RTX and Radeon RX desktops, pairing `ClientAppSettings.json` with a matched framerate cap in Engine Settings delivers the flattest frame-time graph.
How to apply and benchmark in 60 seconds
- Open **Bloxstrap Menu** (install from /download if needed) and go to **FastFlags → FastFlag Editor**.
- Select your target value from `Valid FFlag / DFInt / FString JSON keys` and click **Save**.
- Press **Shift+F5** inside Roblox to open the native microprofiler FPS readout and verify your frame time in milliseconds.
Frequently asked questions
How do I check my actual FPS and frame time inside Roblox?
Press **Shift+F5** in any Roblox experience to toggle the built-in performance stats overlay at the top left of the screen.
What if changing ClientAppSettings.json causes a white screen?
Open Bloxstrap Menu → FastFlags and reset your flags to default, or switch the Rendering Mode back to Direct3D 11.