Gustavo Duarte has written series of interesting articles about the boot process of a computer.
There isn’t much more I can say about this subject myself, other that I found it interesting, so I’m just going to point you directly to these articles instead.
Enjoy.
Since I got my new Lenovo ThinkPad X61, I have discovered that the CPU fan is behaving rather differently than the one I have in my IBM ThinkPad X31. That is the fan makes a lot more noise when idle on the X61.
For the record. I’m running Ubunty Hardy (8.04) on the X61 and Ubuntu Gutsy (7.04) on the X31. Both 32-bit systems.
The first thing I did was checking Launchpad.net for any known bugs. I found bug 224876 to be promising, it’s titled “Hardy does not control the CPU fan properly.”
After reading this thread I ran the tests described myself, which gave these results.
Machine temperature and fan speed when idle (X61):
$ cat /proc/acpi/thermal_zone/THM0/temperature
temperature: 41 C
$ cat /proc/acpi/thermal_zone/THM1/temperature
temperature: 42 C
$ cat /proc/acpi/ibm/fan
status: enabled
speed: 3207
level: auto
After 5 minutes of “yes | sha512sum” (X61):
$ cat /proc/acpi/thermal_zone/THM0/temperature
temperature: 76 C
$ cat /proc/acpi/thermal_zone/THM1/temperature
temperature: 78 C
$ cat /proc/acpi/ibm/fan
status: enabled
speed: 3242
level: auto
As you can see there is as good as no change in the fan speed.
However; doing the same check on my older, one core, IBM ThinkPad X31.
I get this results:
Machine temperature and fan speed when idle (X31):
$ cat /proc/acpi/thermal_zone/THM0/temperature
temperature: 44 C
$ cat /proc/acpi/ibm/fan
status: enabled
speed: 0
level: auto
Actually, the fan doesn’t start until the temperature reach 68 degrees Celsius. Then it will speeds up to around ~3500 rpm, thus keeping the processor at around 70 degrees Celsius during “yes | sha512sum”.
My question is: Why does the fan constantly run on the X61? Is it really necessary to keep the processor cool? I must say I prefer the silence of the X31 when I’m just browsing the web.
Karl Trygve has suggested that this is a result of a new design team and BIOS which is more restrictive than the one found on the X31.
As I mentioned in my last post I had some minor problems with Ubuntu Hardy (8.04) and hibernation. It didn’t always work.
However it now seems like I might have overcome this problem. At first I thought it might had something to do with my docking station. Hibernating while docked, booting up while not and vice versa. The problem was that the machine would freeze during startup after being in hibernation. So to be able to actually see what was going on, I removed the splash screen, and afther this I haven’t had any problems with hibernate what so ever.
Come to think of it, this isn’t the only time the splash screen have caused problems. I had another machine where it refused to boot as long as the splash parameter was set. Luckily, with grub, we are able to edit the boot parameters at boot. Something that wasn’t possible with LILO in the good old days.
To remove the splash screen more permanently than editing grub at each boot. You can,would be to edit the file /boot/grub/menu.1st and remove the word ‘splash’ from the kernel parameters. Just remember that this will sneak its way in the next time you upgrade the kernel. Or rather, Ubuntu upgrades your kernel. as Stian said in the first comment, edit the line “# defoptions=quiet splash” to “#defopts=”quiet nosplash” in the file /boot/grub/menu.1st. Do not remove the leading #.
Please leave a comment if you found this useful.
A few days ago I ordered a Lenovo ThinkPad X61 with 2GB memory option, X6 UltraBase docking station and an optical drive. It arrived the very next day, on a friday, so you can imagine the impact this had on my weekend.
To be fair, the laptop isn’t exactly mine. It belongs to my employer, Jakob Hatteland Solutions.
I’ve specifically asked for the ThinkPad X61 since I’m already familiar with the X-series, I own a ThinkPad X31, and so far I’m happy with it. The ThinkPad-series has the best laptop keyboard I’ve ever encountered. The same can be said about their TrackPoint, that’s why I’m so glad the X-series doesn’t have the dreadful TrackPad.
The machine came pre-installed with Microsoft Windows Vista Business. But for some strange mystical reason it suddenly booted Ubuntu Hardy Heron. This just proves how superior these machines are.
However, there are some flaws that needs to be sorted out. Not in the machine itself, but driver related stuff in Linux. Like wireless. My X61 has a Intel 3945 wireless card, and uses the iwl3945 driver (ipw3945 is obsolete). This workes fine at home, but it isn’t able to connect to the wireless AP at my parents. See bug #183619 in Lunchpad.
Also I don’t trust hibernate 100 percent yet. It has failed a few times, which is a few times to much. But I’ll look more into that later. Otherwise most things seems to work straight out of the box.
I’ll write more about this machine as I stumble upon interesting phenomenons.