Posted by George Wright
Tue, 30 Dec 2008 03:16:00 GMT
Trying out Debian Lenny and its power management seemed to help; I can now get the machine down below 8W, and when using it on half brightness with the wireless card turned on, it sits at around 9W. This isn’t too bad anymore. It’s certainly a lot better than Ubuntu’s 12W in approximately the same circumstances - a saving of 25%!
I’ve now compiled a custom 2.6.28 kernel on Lenny and tried out the ASPM PCI-Express power management code that’s marked as experimental. dmesg reports the following on bootup:
[ 0.172338] ACPI FADT declares the system doesn't support PCIe ASPM, so disable it
After commenting out that bit of code in the kernel just to see what would happen, I then echoed “powersave” to /sys/module/pcie_aspm/parameters/policy, with no noticeable decrease in power usage.
The brightness issue is now sorted. After installing guidance power manager in KDE3 on Lenny things just worked. Sort of. The brightness levels reported by guidance are slightly wrong and the range is wrong. I suspect this is because previous thinkpads have had 7 brightness levels and this one has 15.
The touchpad issue, I’ve concluded, is a limitation of the hardware rather than the software, which is unfortunate. It seems that Lenovo changed the touchpad brand from Synaptics to ALPS with recent models. Unfortunately, ALPS touchpads are nowhere near as good as Synaptics ones, and so I’m stuck with a touchpad that’s a bit of a pain to use. Basically, if you press a button on one mouse, X receives a button press event. However, if you then keep it held down and move the other mouse, the mouse automatically generates a button release event before sending the new motion events. Thank you ALPS.
The fan is now being controlled in userspace using tpfand. I have built debian packages of version 0.94 (from the Ubuntu sources) and I will upload them at some point, along with the fan profile I’m using.
One last thing - the SSD in this machine is blisteringly fast. hdparm brings up around 90MB/s and Lenny cold-boots in about 20 seconds to the kdm login screen.
Posted in Computing | 12 comments
Posted by George Wright
Mon, 29 Dec 2008 01:12:00 GMT
Today I got down and installed Ubuntu 8.10 on this new X300, and things went rather smoothly. I chose to use the ext3 filesystem on the flash disk, and not to create a swap partition (and opted to buy 4GB RAM for it).
In terms of things that work, the list is rather good. The wireless worked out of the box, sleep works, sound works, both batteries are detected, the graphics card works (with 3D acceleration) and general ACPI stuff works.
However, I have noticed a few problems.
First off (and this is really frustrating) - you can’t use the touchpad with the buttons from the TrackPoint (and vice versa). This means you can’t middle-click and drag using the touchpad. It’s frustrating because on my T43p you can, and I got into the habit of doing this because I find the buttons above are more conveniently located than the buttons beneath.
Secondly, it seems that display brightness adjustment sort of works, but keeps tripping over itself. For example, right now my screen is on 75% brightness but I can’t adjust it up or down because the hotkey daemon in KDE 3 thinks it’s on 0% (I’m assuming it’s getting this from ACPI).
Finally (for now) - power consumption seems to be rather high. When I’ve got the display on 0% and the CPU forcibly in powersave and enabled all the powersaving features suggested by powertop, ACPI still reports a power draw of ~12W. In comparison, my X40 drew 6-7W. Whilst I should have tested this before erasing Windows, a quick google search suggests that I should be seeing something more along the lines of 7-8W power draw.
I have also noticed that the fan is pretty much always in the high mode, even when idling, indicating that perhaps the CPU thermal management isn’t working properly. I understand the Intel L7100 is a “special” low-voltage processor that only the X300 uses, so perhaps Lenovo have done some crazy software ACPI hacks to thermally manage these special processors?
This is really bugging me because in Windows on a full charge I was estimated 8h remaining, whereas in Linux I’m being estimated ~4-5 hours.
Posted in Computing | 21 comments
Posted by George Wright
Sun, 28 Dec 2008 01:51:00 GMT
So over the last few days the fan on my T43p has been playing up, and as I’ve had it for about 3.5 years now, I decided it’s probably time to get a new one.
After a quick trip down Tottenham Court Road today, I managed to find a reseller selling the Lenovo ThinkPad X300 which I’ve been pining for ever since its release, and after some bartering managed to get hold of one along with an additional 3-cell battery to replace the CD/DVD drive with.
First impressions of the machine are really positive. The machine weighs less than my X40 did and the screen is much nicer. It’s nowhere near as good as the FlexView UXGA screen on my T43p, but I can’t get everything! Black colours aren’t great and the viewing angle vertically isn’t that good, but for a portable laptop it does the job just fine.
The keyboard is really nice - it gives a decent amount of tactile feedback (it’s better than the one on my T43p I think), and the addition of a touchpad is really helpful (I’ve always preferred them). I especially like that the keyboard is now a full sized one instead of the annoying almost-full size on the earlier X series machines.
In terms of speed, it seems to be pretty zippy. The 64GB SSD is nice and quiet and the performance seems reasonable.
Regarding the build quality - this is the first ThinkPad I’ve owned which was designed by Lenovo instead of IBM. As such, I’m new to such “features” as having a Windows key, an RF switch etc. The case, though, is rock solid and looks incredibly sleek whilst retaining the classic ThinkPad look (which I love). I’m not convinced I like the addition of the LEDs around/under/beside the buttons above the function keys, but I can probably live with that.
I don’t think I’m going to see much of a performance hit going from the 2GHz P-M to this new 1.2GHz C2D, especially given that my usage pattern doesn’t tend to involve single threads munching the CPU for a long time. We’ll see how it fares in due course.
All in all, a very happy bunny and I’d like to say this is the best ThinkPad I’ve owned yet, but it’s probably too early to say.
Next up - Ubuntu installation. Vista angers me.
Posted in Computing | 3 comments
