Re: ido-switch-buffer is slow with many buffers; others are fast

[Dmitry Gutov]

On 14.11.2020 18:34, catern@catern.com wrote:
> I recently became annoyed enough in my 1000-buffer Emacs instance to
> start profiling things.
>
> I was disappointed to find that the buffer-switching slowness I'd seen
> is the fault of ido-switch-buffer.
>
> ido-switch-buffer takes over a second before it starts accepting user
> input, with this many buffers.

Which Emacs version are you using?

A fix that seems relevant has been added in df4991093b9 recently. But 
it's only in Emacs 28 thus far.