Boot speed in Arch

I've noticed that my bootups seem to be getting faster and faster. I remembered installing something that was supposed to automatically adjust the boot process over time and reboots, but I couldn't remember what it was. 

* EDIT: I remembered what I did to speed things up, from the Arch wiki :

# systemctl enable systemd-readahead-collect systemd-readahead-replay

Anyway, I ran systemd-analyze and compared the results to a post from a couple weeks ago, and man I was definitely right, just the four top entries are below:

Two weeks ago:

$ systemd-analyze blame

 7977ms NetworkManager.service
 2796ms colord.service
 2788ms bluetooth.service
 2728ms systemd-logind.service

Today:

$ systemd-analyze blame

1923ms systemd-modules-load.service
 769ms systemd-binfmt.service
 589ms NetworkManager.service
 555ms systemd-udev-trigger.service 

So these four entries alone show a change from about 16 seconds to about 3.