Vim Scrolling Slowly - performance

Question

Vim is acting slow when I scroll. The cursor skips some lines when I'm pressing j/k continually.
I'm using xterm and urxvt. In both vim acts like this.
This happens locally, with small or big files. I do use Control + F/B they work just fine.
EDIT: ttyfast in small files did the trick but in bigger is the same. When running without customization it goes allright.

Answer 1

:set lazyredraw will buffer screen updates instead of updating all the time. I generally enable it when I'm doing a complex macro playback. Might help you here.

Answer 2

Have you tried the 'ttyfast' option? See:
:help 'ttyfast'
for help, and:
:set ttyfast
to enable it.
Also, what version are you using? And have you tried this with no customizations to see if something you've set is interfering?
Run it like this to omit any of your vimrc settings and plugins:
vim -u NONE
EDIT: If removal of customizations fixes it. Remove things iteratively until the behavior returns. Start by narrowing it down to either a vimrc problem or to plugins.

Answer 3

I had this problem only when using the pylint.vim plugin with syntastic. The only thing I can find that's helpful (other than disabling the syntax checker) is to disable highlighting current line:
:set cul!
This sped up my scrolling significantly.

Answer 4

Regexp Recomputation Bug on Vim
Depending on the version of Vim you are using, you might be affected by a regexp recomputation bug, whose main culprits seem to be highlighting the cursor line and displaying relative line numbers:
set relativenumber
set cursorline
The web is scattered with threads reporting this issue (here, here and here). The issue seems to be exacerbated if one also uses syntax highlighting.
Personally I just solved my slow scrolling problems by disabling relativenumber by adding this to my vimrc:
set number
My Vim
My Vim is the one provided by the vim-nox package version 2:7.3.547-7 on Debian 7.9. Typing :version in Vim yields:
VIM - Vi IMproved 7.4 (2013 Aug 10, compiled Dec 11 2014 03:17:52)
Included patches: 1-488

Answer 5

If the other suggestions don't work, it may be a problem with your terminal. My gnome-terminal on Ubuntu was scrolling much slower than PuTTY with the same file.
If you're using Ubuntu's default gnome-terminal, you might want try another terminal program. urxvt both worked for me (terminator had similar problems):
$ sudo apt-get install rxvt-unicode
$ urxvt
The major downside is that it doesn't look very good. You can try the advice here to make it look a bit better
References:
Slow tab switching in Vim with large terminal
The GNOME Terminal is very slow in GNOME 3 [AskUbuntu]
Edit: It seems that the real solution for me may be to stop full-screening my terminal when using vim.

Answer 6

Late answer, but the above did not help me.
First, figure out what the exact problem is rather than flailing about disabling random stuff. Vim has a super nifty profiler.
:help prof
will get you started, but I did
:prof start ~/vim_profile
:prof func *
:prof file *
Then did a bunch of super slow scrolling. Afterwards,
:prof exit
You can then look at the vim_profile and see exactly what the problem is. In my case it was the matchparen which I fixed by adding
set noshowmatch
to .vimrc, but could be different for you.
As an aside, after I got vim itself tuned, I was able to improve performance more by using a different terminal (iTerm2, or Alacritty) instead of the built in one.

Answer 7

My scrolling was fixed after disabling parenthesis highlighting. In ~/.vimrc put:
let loaded_matchparen = 1

Answer 8

Check your silent mappings as well. If you have mappings starting with j, k, h,l then that may also cause a momentary lag.

Answer 9

I was running vim on a Raspberry Pi 1. Disabling this one line sped things up for me:
set foldmethod=syntax "slow!

Answer 10

I came here with similar scrolling problems. I really didn't want to turn off syntax highlighting altogether, so I disabled "set cursorcolumn" and "set cursorline" and my scrolling became much faster.