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.

Analyzing the boot process

Something I want to investigate further in the future, so I'm making a note of it here.
Arch uses systemd to initialize the OS, which has some cool features for analyzing the boot process and showing where the time is taken.

Show the hogs:

$ systemd-analyze blame
  7977ms NetworkManager.service
  2796ms colord.service
  2788ms bluetooth.service
  2728ms systemd-logind.service
  1558ms polkit.service
   516ms systemd-tmpfiles-setup.service
   488ms tmp.mount
   486ms systemd-binfmt.service
   484ms dev-mqueue.mount
  ...

Create a plot of processes:

$ systemd-analyze plot > ~/plot.svg
$ kde-open ~/plot.svg

There's also some way to create a "bootchart" but it may required a custom kernel or something, I don't remember.