Significantly slower than st

[rouanth]

$ ls -lh file
-rw-r--r-- 1 rouanth rouanth 39M Jan  7 15:25 file

I've ran base64 file multiple times so it would be properly cached. Then I've ran time base64 file on st with the following results:

real    0m9.786s
user    0m0.500s
sys     0m2.600s

Multiple attempts have shown that st outputs consistently in 9 to 10 seconds.

Then I've ran the same command with alacritty off-screen:

real    1m1.395s
user    0m1.407s
sys     0m5.950s

If it is present on the screen, it takes

real    1m25.855s
user    0m2.003s
sys     0m8.593s

Multiple attempts have confirmed these numbers.

I use Arch Linux, recently updated. alacritty was built just now from AUR. I use the default configuration file. st is built from commit e44832408bb3 dated November 24th.

lspci | grep VGA says

00:02.0 VGA compatible controller: Intel Corporation Atom Processor Z36xxx/Z37xxx Series Graphics & Display (rev 0e)

Both terminal emulators are run under XWayland.

I'm ready to provide additional information if requested.

[ton]

I can confirm this.

Using st (latest from git), time -p base64 alacritty outputs:

real 1.29
user 0.11
sys 1.01

Using alacritty itself:

real 56.54
user 0.40
sys 2.65

I am running Arch Linux as well. lspci | grep VGA output:

04:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Cypress PRO [Radeon HD 5850]

Tests were run multiple times to warm up caches. alacritty was built in release mode.

[gnunn1]

In my testing alacritty is considerably slower then other terminal emulators on Linux, when I run time find /usr I see the following results:

alacritty: real 0m58.104s, user 0m0.590s, sys 0m1.147s

xterm: real 0m33.216s, user 0m0.717s, sys 0m1.127s

gnome-terminal: real 0m2.845s, user 0m0.367s, sys 0m0.817s

One reason why gnome-terminal is so fast is that I believe the VTE widget renders to a fixed frame rate in an almost vsync fashion and thus doesn't waste time rendering intermediate frames. I think this is a good design choice personally.

[Pyrolistical]

Probably related to #110

[Muffindrake]

Slow mesa implementation is to blame here. This is a duplicate of #125

[jwilm]

Thanks for the diagnosis

[samarthkulshrestha]

Yeah, its true, even opening and closing the terminal somehow feels snappier when I use st. Alacritty sometimes takes a sec to open.