I recently switched from ubuntu to manjaro, and while installing something from the AUR, noticed that it took a long time to install something that wasnt very big.
Did it compile from source?
Almost all the packages from AUR compiled from source files, there are some that are binaries though.
You can also do this command: sudo pacman-mirrors -g
to scan all the mirrors and auto use the one that has the lowest ping.
Well...that's not very good :-( this is a dual core pentium so i dont really want to compile stuff...
How big are arch's repos conpared to, say debian or ubuntu?
The arch repos are binary and have more or less the same stuff that other distros have. The AUR is a user repository which has stuff you won't find in the normal arch repos. So it saves you having to build it yourself and sort our dependencies, it shouldn't be any slower than using ubuntu or something else.
I use manjaro, not arch so I'm not sure the arch repos, so this is just an assumption, I could be completely wrong.
I use manjaro too, and yes, the AUR saves you from building packages yourself.
I'm concerned more about the compile times on a dual core pentium
It all depends on the package, some AUR packages are small and some are big.
https://wiki.archlinux.org/index.php/Makepkg#MAKEFLAGS Here are some ways to speed up compiling.
You can enable multithreading on your compression to speed it up.
do the following commands:
sudo nano /etc/makepkg.conf
add - --threads=2 to COMPRESSXZ
COMPRESSXZ=(xz -c -z - --threads=2)
do CTRL+O to write changes
then do CTRL+X to exit nano.