On Sat, Sep 24, 2011 at 1:16 AM, Eli Zaretskii
<eliz@gnu.org> wrote:
> Date: Sat, 24 Sep 2011 00:18:00 +0800
> From: Le Wang <l26wang@gmail.com>
> Cc: help-gnu-emacs@gnu.org
>
> > (setq-default bidi-display-reordering nil)
> >
>
> This helped me with my slow scroll issues. Holding down arrow on a fully
> maximized frame on a 1080p monitor was spiking my duo-core CPU to 20-25%.
> Scrolling text. 50% of one CPU. Just to scroll text.
Scrolling how (by what commands)?
next-line
What kind of text? What was the
major mode in that buffer?
emacs-lisp large file
I also use full font-lock salad colors with "Consolas" font on Windows. Also I use several minor-modes that add pre or post-command-hooks.
Some modes are more expensive in redisplay
than others. It is impossible to tell whether 50% of a core is
unreasonably high without knowing these details.
Additionally I have these scroll related settings. Some of which I added after realizing scrolling was slow, others I had previously to enable smooth scrolling.
(setq hscroll-step 1
scroll-conservatively 10000
scroll-preserve-screen-position t
auto-window-vscroll nil ; speedup down scroll
scroll-margin 10
redisplay-dont-pause t ; this will be default in emacs24
)
> And it would start jumping around almost right away.
Does it behave better if you set redisplay-dont-pause to a non-nil
value? This will be the default in Emacs 24.
It's not making a noticeable difference. Although it sounds like a good idea.
To be clear, I get perfectly smooth scrolling now with bidi-display-ordering set to nil. And my CPU usage doesn't exceed 12% while scrolling. So things are good now.