Battery Lifetime Lenovo T61 with 7-Cell-Battery
So after used my T61 for quite a while now I wanted to give a update about my experience with the battery lifetime of this laptop. In almost every review about the T61 the biggest issue was its short running time on battery. And that’s at least not totally wrong. The T61 won’t ever become a battery life wonder… But after taking proper care about the Lithium ion following the Maintenance Guide on thinkwiki.org, with the help of the nice Kernel module tp-smapi, I’ve got a maximum capacity of about 74W.
Experimenting with bleeding-edge kernel sources like kamikaze-sources and its successor zen-sources and following some tips under www.lesswatts.org leaded to an energy consumption of about 16-18Wh with WiFi and even 14Wh without. Of course you get this values only with darkened backlight (use xbacklight instead of /proc/acpi/ibm/brightness see here why).
So all this together gives me something like 3 to 3 1/2 hours of surfing and working in the Uni… of course much lesser if I compile the latest KDE 
. But I thinks that are pretty reasonable results for an laptop with this performance.
Back again!
I kind of neglected my Blog in the last time. I started to study and so I had to arrange some things (trying to convince my new internet provider that it is not nice to let their customers wait more than a month for their connection…) But now everything seems pretty good: I’m surfing with 16 Mbit/s and I’m really enjoying my physics studies at the University of Potsdam.
At the moment I’m playing a little bit around with a svn-Snapshot of KDE 4 and I’m actually really impressed by the appearance of the new KDE! It’s just an awesome work which this guys from Oxygen and Plasma are doing. I couldn’t have a closer look till now, because i just got it running a few minutes ago and there are still some issues with kind “mixins” from the “old” KDE which I’m using currently as my main desktop. I have i.e. 2 Taskbars in my KDE4 at the moment, the KDE 3.5 Kicker one and the new Plasma one… kind of weired. But I try do figure this out. So I might be able to switch to a new shiny desktop environment or at least exploring the new features much more in depth. I’m also really keen on looking how Amarok 4 is evolving. So lets see if KDE4 becomes the “best KDE” ever… At least it has a realistic chance.
Disk Speed Issues Solved! (at least for me)
I finally found out why I had such a bad disk performance! Actually I wanted to care about this problem later, because I’m traveling at the moment and therefor I wanted to have a stable system. But it got so annoying that I decided to take the risk of breaking the system totally and so I did some more serious research. A simple hdparm -tT /dev/hda revealed the following:
/dev/hda:
Timing cached reads: 7932 MB in 1.99 seconds = 3985.16 MB/sec
Timing buffered disk reads: 8 MB in 3.02 seconds = 2.60 MB/sec
So what the heck… why only 2.6MB? And by the way, why is it hda shouldn’t it be sda for a SATA disk?
It turned out that I still had compatibility mode activated in my BIOS, so the kernel recognized the SATA disk as a old style ATA disk which apparently caused this incredible low performance. After 2 minutes of changing /etc/fstab and the boot options in GRUB the hard disk was running with nice 44 MB/s.
What do we learn out of this? Don’t blame always the operating system! Maybe it’s just a wrong BIOS option…
T61 and Linux
So after quite a bit time playing around with my T61 and Gentoo I’m really surprised that there are actually so less problems. I admit that you have to use very often bleeding edge drivers (i.e. to get sound under ALSA working), but hey thats brand new hardware! And the awesome documentation on the Gentoo Wiki about the T61 and ThinkWiki helped a lot to get most of the things running. I just can encourage everybody who has a Thinkpad (preferable a T61) to contribute his experiences to this two projects in order to get a even better Linux support on this notebook. There are still some unsolved issues about suspend/hibernation, the APS, Nvidia Drivers and some other minor stuff. But nothing to big, so we can hope to get them solved in a few weeks/months.
But apparently Linux has a issue with SATA performance under x86_64 (link1, link2), which is quite annoying and I’m thinking about switching back to i386 and see how it looks there…
