Showing headlines posted by D

If you simply want to adjust a service's priorities, here is how to do it in three simple steps.

I found some easy tweaks I haven't seen anywhere else to significantly improve the owncloud performance. I'm assuming you're already using the usual tweaks such as using cron.php.

The author tells the story of how he discovered a fix for an issue with many Samsung laptops with Linux. He shows how a program can solve the problems and e.g. enable lid detection, correctly react to an (un)plugged AC cable, and possibly improve performance.

A new app developed by a German University Stuttgart student during his PhD thesis research prevents people from unlocking your phone by looking at grease stains on your screen.

Suspending to RAM is allows the system to quickly wake up. But Suspend to Disk allows the system to completely power off, saving more power. That's why I've written a small script for modern Linux systems, which wakes up the system from S3 (memory sleep) and puts it into S5 (hibernation) mode. Also, it prevents you from losing data, because eventually your system's battery will run out. This script helps.

The just released version 18 of Firefox no longer works with older systems. Read on for details.

So I finally got to test Google Talk Video on the Nexus S. The result is simply: Excellent. It feels like a completely new era of communication has begun. Walking around with your phone in your hand having a nice, fluid video conference is just great.

These are some commands for frame sequencing to top-bottom or side-by-side 3D video transcoding, fast with mencoder or slow and flexible with ffmpeg and imagemagick.

Control groups are really, really great. They can effectively make your system act as if it were two or more systems in one. It's like virtualization without all the overhead. I will show you how to do it manually step by step so you can learn how it works.

Con Kolivas created an lrzip archive of all the sources of all 2.6 linux kernels. And guess how much space and time it took? A hint: All sources in a tar are 10.3 GB. The 2.6.39.1 kernel is 73 MB as a tar.bz2 archive. Now it would be less than that times 39, because the first kernel was smaller (just 32 MB). He are some actual numbers: I think a bzip2 would be about 2GB. An xz archive is about 1.4 GB and takes 2 hours. Now that I gave you all these numbers let's see how much it really is... (make a guess an click the link)

A small script loop on the kindle to log the battery consumption and then plug that data into gnuplot (with screenshots).

I've previously tested alsa code that allows for audio playback without causing IRQs in combination with the (less new) pulseaudio code that allows for almost CPU-wake-less playback. A bit more tuning allowed to increase the power savings to 0.4 W. Check inside for the whole updated story with full powertop logs!

Let me start at the beginning: Recently, pulseaudio not only switched to a more power efficient (and otherwise) timing system. It also provided the infrastructure to use ALSA devices without causing _any_ interrupts, so you CPU can stay longer in standby mode, saving you power and avoiding playback glitches. With kernel 2.6.38 the first driver supports this infrastructure, the snd-hda-intel driver. This is what I tested for power efficiency in this article...

It's not possible directly right now due to limitations of the existing GMA 500 drivers (IEGD, PSB, ...) and probably some other VAAPI drivers as well. But if you have mplayer running with vaapi, it's really easy - Because you can set up xbmc to use external players with XBMC 10 as described here.

Laptop_mode is actually a great thing, as it activates a few powerful power saving modes in Linux, most importantly disk power saving and delayed writes. But if you use it with out of the box settings, there are two major bugs in Laptop Mode Tools, which could cause your disk to crash and are the reason it's normally disabled. Now let me show you how to work around them and easily save 2 W of power:

In the following post I will explain how to use cpu tuner, a completely free and open source app for android. All you need is root and some time. It's a follow up on and summary of my various related posts you can mostly see below ("related posts") on working with governors to increase power efficiency in Linux. This is of course something that a) Linux and b) Android and c) your phone manufacturer should already have done. But as they didn't...

It's been all over the news that Google is starting a pilot program for it's Chrome OS, which I expect to be out within a few months. The pilot program is probably meant to get the last polish for the system. As my readers will know I'm always excited about new technology, especially dealing with Linux. But here's why I ended up not even trying to get into the program:

CPUfreq is the part of the Linux kernel that changes your CPU's frequency to save power or increases it to make your system run faster. Obviously the settings you use there are essential for you performance and battery consumption. I read an extensive article by IBM some time ago analysing the different Linux cpu frequency governors. It makes lots of fancy tests and has great diagrams etc. What it boils down to is that these are the perfect setttings for low power at high performance in Linux.

Questioning the necessity for Wayland and the wiseness of the choice has become a phenomena, especially after Mark Shuttleworth annouced Ubuntu's plans to eventually switch to Wayland. Following I will provide a concise reasoning why we want Wayland. At the end there are some more links for further reading.

Find out what I like and dislike about the android system after a critical review on the Samsung Galaxy 3. And at the end there's a list of my favorite apps. ;-)