How to improve into vim of MacOS Mojave the speed of vertical scroll with bottom/up keys?

I transfer the original post from StackOverflow (Original post ) to here since this is about Apple specificity. I have a new macbook with Mojave and vim already installed. Unfortunately, even for small source files, the cursor is very fast when I browse the current part of file where I am located **but it becomes very slow when I am over this current page (the same thing occurs if I am over or lower this part) with down/up keys.** I don't talk about "mouse scrolling speed" but scrolling with down/up keys. I saw and tried to apply different suggested solutions on web but none of these work for me (disable cursorline, using an empty ~/.vimrc , etc ...). Maybe threre is a conflict with some options in my ~/.vimrc. Here below my ~/.vimrc: set encoding=utf-8 scriptencoding utf-8 set ic command Il :%s/^/\=line('.'). ' ' set hlsearch set shiftwidth=2 " number of spaces to use for auto indent set autoindent " copy indent from current line when starting a new line set nu syntax on " syntax highlighting set backspace=indent,eol,start " delete with backspace "TOhtml let html_use_css=1 let html_number_lines=1 let html_no_pre=0 highlight DiffAdd cterm=bold ctermfg=10 ctermbg=17 gui=none guifg=bg guibg=Red highlight DiffDelete cterm=bold ctermfg=10 ctermbg=17 gui=none guifg=bg guibg=Red highlight DiffChange cterm=bold ctermfg=10 ctermbg=17 gui=none guifg=bg guibg=Red highlight DiffText cterm=bold ctermfg=10 ctermbg=88 gui=none guifg=bg guibg=Red I have changed into System Preferences the delay between 2 repeated keys to a small value : So, into the default Terminal of Mojave macbook, I can move quickly with left/right keys on the command line. Is there a relation between this small delay I have set and this slow scroll vertically with donw/up keys into vim ? Another bug which must be known is that some commented code parts (for example when editing Python code with vim) **appears as not commented when scrolling with down/up keys and also the contrary occurs** : anyone has already got this strange behavior ? this problem doesn't happen when I browse file with CTRL+F or CTRL+B shortcuts. Any help is welcome, Regards **UPDATE 1 :** Finally, I get to increase speed with the following link : https://rehmann.co/blog/better-key-rates-osx/ I decided to switch to iterm2. So, as partial conclusion, the solution was to set fatest options in System Preferences and put into ~/.bashrc : #disable special characters when holding keys defaults write NSGlobalDomain ApplePressAndHoldEnabled -bool false # normal minimum is 15 (225 ms) defaults write -g InitialKeyRepeat -float 10.0 defaults write NSGlobalDomain InitialKeyRepeat -float 10.0 # normal minimum is 2 (30 ms) defaults write NSGlobalDomain KeyRepeat -float 1.0 defaults write -g KeyRepeat -float 1.0 ############# Enable spees ###################### **It might be even too fast**. That's why I wonder **if there is a way to apply this big speed only for selected keys**, i.e in my case, **I would like to have this behavior for only down/up and left/right keys** and NOT for the others keys (letters or special characters) ? Is it possible to get this behavior ? **UPDATE 2 :** Ok, I have finally found the trick : in iterm2 terminal, there is a GPU rendering option on below image : If you have no power on, GPU rendering was by default disable like, so uncheck the first box to be able to benefit from GPU rendering when computer is on battery : That's all !