You know the feeling — you submit a prompt, the spinner starts, and instead of smooth animation you get a choppy, stuttering mess. You check your CPU. It's idle. You check RAM. Half empty. You toggle every terminal setting you can find. Nothing helps.
If you're on Windows 11 and Claude Code feels like it's running through molasses, you're not alone. A detailed issue report (#76745) with instrumented bisection data confirms the TUI render loop has degraded ~2× between versions 2.1.159 and 2.1.207. The median frame cadence dropped from a smooth 62 ms (~16 fps) to 99–109 ms (~9–10 fps) — and that's just the spinner. During token streaming it's worse.
The Regression in Numbers
The reporter, running Windows 11 Pro on a Ryzen 7 7800X3D with an RTX 4080 SUPER, built a ConPTY harness to timestamp every output chunk. The data shows three distinct degradation stages:
Version
