Great news reached me a few days ago when I read that there is a workaround for getting suspend working under Linux on various Acer TimeLine notebooks. See bug #405120 and follow the easy instructions. I can verify that it works nicely on the TravelMate TimeLine 8371 which I possess. There is a certain sense of irony in saying that this is good news though. Acer should have known this from the start and verified that Linux would work correctly on their notebooks, I can’t imagine that would have taken much effort for them. Even if they support only Windows, they could have made some of their customers happier if they prevented the problems, but it doesn’t surprise me one bit because I’m already quite familiar with Acer’s incapability to work in customer driven way.
Besides that, to follow up on my previous post I’ve done some new power consumption measurements on my TravelMate TimeLine 8371, this time with both beta releases of Kubuntu and Ubuntu 10.04 a.k.a. Lucid Lynx. The procedure was as follows, I downloaded the 64-bit desktop images of both Kubuntu and Ubuntu. I installed them both, I didn’t run them from the Live USB so that I would get accurate measurements. Important difference between vanilla 8371’s and mine is that I replaced the hard disk drive in my notebook with a Intel X-25M (second generation Postville) solid state drive. In both cases I disabled Bluetooth manually ith the key on the keyboard, because it’s always enabled by default. After a standard installation I didn’t do any modifications (except for the suspend workaround mentioned earlier to test if it would work) and installed PowerTOP, then I started measuring. PowerTOP was started with the sudo command, of course. The measurements which are mentioned were achieved after implementing the various suggestions PowerTOP gives for saving more power. I mean only the suggestions which can be implemented on the go at the press of a key, on both Ubuntu and Kubuntu PowerTOP reported that several processes where writing to certain files on the disk which kept the disk out of power saving mode, I didn’t bother doing anything about those. Because I have an SSD instead of a hard disk drive it shouldn’t make as much of a difference anyway.
On Ubuntu I reached 6,2 W with WiFi enabled and having set the monitor to it’s lowest brightness manually with the keys on the keyboard. On Kubuntu I initially reached 7 W. That was reached after decreasing the brightness to the lowest level manually as well, it should be noted that Kubuntu doesn’t dim the backlight as aggressively by default as Ubuntu does. For some reason WiFi was disabled, the hardware button to enable it didn’t respond and the WiFi interface didn’t come up by default as soon as Kubuntu booted while it did with Ubuntu. Nothing was wrong with my hardware, because Ubuntu worked fine. Possibly my problem is related with the problem described here on the kubuntu-devel mailing list. Desktop effects were enabled manually on KDE, I’m not sure if Ubuntu enables them by default but I think so.
I decided to see if suspend would work. After suspending and then awaking my notebook I noticed that for some reason the WiFi interface came back up. When it came up again I enabled WiFi power saving when PowerTOP came up with the suggestion. After that PowerTOP consistently displayed power usage varying between 5,5 and 5,7 W for a period of ten minutes, for a moment it reached 6 W and then went back to 5.7 W again. I’ve never seen it reaching that low on Ubuntu, it makes me wonder if the measurement is reliable because Ubuntu doesn’t have the bug which causes the audio device to be active 100% of the time.