How to boot real fast?

[Johnny Who]

When I first installed sabayon, it would load gnome 3 from cold boot in net 47 sec. Now it takes one and a half minutes. It may sound paranoid, but I do need a faster boot as:
1) I have a laptop
2)I want to impress people used to slow boot times of M$ Windows
Well, I have followed the wiki article on tweaking and performance boosting (apart from the DNS server part), used rc-update like a chainsaw and disabled many (and I mean many) daemons and processes from runlevel boot and default, set rc_parralel to yes and compiled a light custom kernel in which I dropped support for drivers I do not need. The kernel is up and running in 30 secs to login screen, which I can reduce even further if I stop using lvm (I did not know that when I installed SL with automatic partitioning) and drop the intiramfs somehowHow can I do that?
But the real problem is that gnome is too slow to start, nearly 40 secs (like most other DEs I have tried, including xfce). My DM is lightDM. Any suggestion on improving that load time would be greatly appreciated.

[micia]

Uhm, I don't know about GNOME, but I'm using Xfce with Slim login manager and the desktop environment is up and running in about 7 seconds, on an Acer netbook, Atom processor and generic video drivers (horrific Poulsbo video card).

Anyway, the most of the boot time are taken by the desktop environment and kernel loading, so you either reduce that or will have little benefit, I honestly think your desktop environment startup time is far too long, 40 seconds are a lot of time.

[Johnny Who]

Do yo have an ssd?

[micia]

No, just plain rotational disk, 5400RPM.

Anyway, you mean that it takes about 40 seconds for just GNOME to boot, or you mean that it takes about 40 seconds to get to a working desktop environment, including the login screen and the system boot itself?
I got the idea that you meant the first one, by your post.

[Johnny Who]

Well, I get about one and a half minute to get to a working environment from cold boot with autologin enabled. The kernel loads in 45sec, another 15 for the dm (lightdm/gdm/lxdm, I am constantly hopping from one to the other) and I have Gnome up and running in another 30 secs more or less... Note that I have preload installed and my disk is kinda slow, 5400rpm (as yours). I have used slim in the past, but abandoned it because when autologin-enabled it would drop me to a console.

[manifesto]

I check mine and found :
0 -> 9s for initramfs to kernel boot
9s -> 44s boot until kdm ready to log in (35s)
44s -> 1m52 to have KDE ready to use (which looks huge time 1m and 8s !)

I think there are too much modules loaded on initramfs and I should find time to build a small one !
There should be some way to shorten kernel boot to login screen but I cant find a way to trace boot.
Bootchart is available on gentoo and not sabayon
My /var/log/boot.log is empty do you get the same empty file ?

For KDE I tried to logout login and then login time drop to 17s ... I think I should cleanup some .kde4 files.

Having start => kdm login ready of 30s looks good timing and then KDE or GNOME login should not exceed 30s.

[micia]

Strange, without any particular customization, no custom kernel and no parallel RC either, I get into a working graphical envioronment in about 30 seconds.
I use Xfce and Slim as my login manager, with ext4, memory usage is 150MiB on clean desktop (including every panel applet and conky).