Alacritty—I used it for a while but I didn’t really notice a performance advantage. I’m not sure what people are doing where terminal throughput really matters, and when Dan Luu did latency tests (admittedly, this was a while ago), Alacritty was middle of the pack.
Quite some time ago (~15 years?), I needed to repeatedly recompile SBCL from scratch, a process that produced multiple megabytes of output per second. I found that the gnome-terminal (which I was using at the time) increased compile time by ~4x relative to redirecting the output to /dev/null. Xterm only increased compile time by ~20%, but rxvt-unicode had no measurable overhead, so I switched over and only reconsidered when it became fashionable for CLI tools to use emoji in their output.
Stdout is frequently buffered slightly, but yeah, once you exceed it your `print(...)` line becomes blocking, and the execution moves to your terminal until it displays or discards it, freeing room in that buffer.
With large amounts of output, that can be a massive amount of time. As a really simple example, try `time dd if=/dev/random bs=1k count=1000` to print a megabyte of random data, vs `... > /dev/null`.
What about redirecting to a file? I would be worried that my eyeballs might not even be able to keep up with megabytes per second, so having the output in a file would seem more useful anyway.
You can enable ligatures in iTerm under Prefs > Profiles > Text. (Unfortunately ligatures are not supported by the Metal-based GPU renderer, which is faster than the legacy renderer.)
If you're on Wayland with properly set up GPU drivers, Alacritty was a top-tier performer on my benchmarks (sorry, didn't save them) but can be pathological in other scenarios.
Were you measuring throughput or latency? I’d expect to see good throughput measurements for Alacritty, I just think that only matters if something else has gone wrong (no terminal is slower than my eyeballs).
Alacritty—I used it for a while but I didn’t really notice a performance advantage. I’m not sure what people are doing where terminal throughput really matters, and when Dan Luu did latency tests (admittedly, this was a while ago), Alacritty was middle of the pack.