tmux Scroll vs Terminal: 10K Line Benchmark Results

#tmux #terminalemulator #benchmarks #performance

The Myth of tmux Scroll Overhead

A colleague insisted tmux was "destroying his scroll performance" when tailing logs. He'd switched to running everything bare in iTerm2, convinced the multiplexer layer was the bottleneck. But when I tested scrolling through 10,000 lines of dense output, the results flipped his assumption.

tmux's scroll-back buffer isn't the problem most people think it is. The terminal emulator's rendering engine matters far more than the multiplexer sitting between your shell and the display. In fact, across four different terminal emulators running identical tmux configurations, I measured a 3.8x difference in scroll responsiveness — while tmux vs. no-tmux on the same emulator showed only a 1.2x gap.

The real performance story is about GPU acceleration, text shaping engines, and how your terminal handles rapid frame invalidation. Not the tmux layer.