Terminal latency (2017)

But most terminals (st, alacritty, hyper, and iterm2) are in the range where you might expect people to notice the additional latency even when the machine is idle. These measurements aren’t anywhere near the worst case (if we run off of battery when the battery is low, and wait 10 minutes into the compile in order to exacerbate thermal throttling, it’s easy to see latencies that are multiple hundreds of ms) but even so, every terminal has tail latency that should be observable. Just so we can compare the most commonly used benchmark (throughput of stdout) to latency, let’s measure how quickly different terminals can sink input on stdout:

Alacritty was tested with tmux because alacritty doesn’t support scrolling back up, and the docs indicate that you should use tmux if you want to be able to scroll up.

Source: danluu.com