I don't think so, zsh is faster than bash for me without rc files:

❯ repeat 5 { time bash --norc --noprofile -c exit }
took 0,011s (100% cpu)
took 0,011s (98% cpu)
took 0,011s (100% cpu)
took 0,011s (100% cpu)
took 0,011s (99% cpu)
❯ repeat 5 { time zsh -fc exit }
took 0,002s (89% cpu)
took 0,001s (90% cpu)
took 0,001s (92% cpu)
took 0,001s (92% cpu)
took 0,001s (91% cpu)

same with rc files:
❯ repeat 5 { time bash -c exit }
took 0,028s (89% cpu)
took 0,022s (100% cpu)
took 0,022s (100% cpu)
took 0,022s (100% cpu)
took 0,023s (99% cpu)
❯ repeat 5 { time zsh -c exit }
took 0,008s (91% cpu)
took 0,008s (92% cpu)
took 0,007s (92% cpu)
took 0,007s (92% cpu)
took 0,005s (91% cpu)

Julien

Le ven. 7 déc. 2018 à 03:57, Peng Yu <pengyu.ut@gmail.com> a écrit :

> On Thu, Dec 6, 2018 at 8:20 PM Sebastian Gniazdowski
> <sgniazdowski@gmail.com> wrote:
> >
> > On Mon, 3 Dec 2018 at 17:28, Peng Yu <pengyu.ut@gmail.com> wrote:
> > >
> > > Hi,
> > >
> > > The following example shows that zsh startup time is much slower than
> > > other shells. Can this be improved to at least as fast as bash?
> > >
> >
> > Is it the last zsh version that's being tested? There was 2x startup
> > improvement at 5.4 or something like this.
>
> Here is the version. I have not set up zsh to do anything fancy. I
> guess the slowness of startup is because zsh does too many things
> upfront and has more features than other shells, and the increase in
> startup time the price that zsh has to pay.
>
> $ zsh --version
> zsh 5.6.2 (x86_64-apple-darwin17.7.0)
> $ cat ~/.zshrc
> # Lines configured by zsh-newuser-install
> HISTFILE=~/.histfile
> HISTSIZE=1000
> SAVEHIST=1000
> bindkey -e
> # End of lines configured by zsh-newuser-install
> # The following lines were added by compinstall
> zstyle :compinstall filename '/Users/pengy/.zshrc'
>
> autoload -Uz compinit
> compinit
> # End of lines added by compinstall
>
> > Also, Zplugin can load plugins after prompt, I load 20 plugins, and my
> > startup times are:
> >
> > repeat 5 { time /usr/local/bin/zsh-5.6.2-dev-1 -i -c exit }
> > /usr/local/bin/zsh-5.6.2-dev-1 -i -c exit  0,09s user 0,04s system
> > 117% cpu 0,111 total
> > /usr/local/bin/zsh-5.6.2-dev-1 -i -c exit  0,10s user 0,05s system
> > 119% cpu 0,130 total
> > /usr/local/bin/zsh-5.6.2-dev-1 -i -c exit  0,11s user 0,05s system
> > 121% cpu 0,129 total
> > /usr/local/bin/zsh-5.6.2-dev-1 -i -c exit  0,09s user 0,04s system
> > 115% cpu 0,119 total
> > /usr/local/bin/zsh-5.6.2-dev-1 -i -c exit  0,09s user 0,04s system
> > 117% cpu 0,109 total
> >
> > I even load prompt after a default prompt, ~ 100 ms after it. The
> > Star-Trek console-like impression this gives can be visible here:
> > https://asciinema.org/a/156726 – much is going on, automatically, in
> > background.
> >
> > > --
> > > Regards,
> > > Peng
> >
> > --
> > Sebastian Gniazdowski
> > News: https://twitter.com/ZdharmaI
> > IRC: https://kiwiirc.com/client/chat.freenode.net:+6697/#zplugin
> > Blog: http://zdharma.org
>
>
>
> --
> Regards,
> Peng
>