Phoronix: NVIDIA vs. Nouveau Drivers On Ubuntu 13.04
, 1 min read
In Phoronix there is an interesting comparison between Nouveau and proprietary NVidia graphics driver, see NVIDIA vs. Nouveau Drivers On Ubuntu 13.04.
A Praise for IceWM
, 1 min read
Since more than ten years I use IceWM, a clean and compact window manager for X. I can only recommend it. IceWM in its own words: The goal of IceWM is speed, simplicity, and not getting in the user's way. These goals are nicely met. Among the features of IceWM: multiple workspaces easily move…
0x5f3759df - calculating inverse square root
, 1 min read
An interesting article in Wikipedia on calculating a first approximation of the inverse of the square root Fast inverse square root, or 0x5f3759df - calculating inverse square root
linux-3.9: Compile times
, 2 min read
Compare linux-3.8.4: Compile times. This time we compiled Linux kernel 3.9 and used time make -j 20 according Compiler Speed-up. My 8-core machine is fully loaded, as can be seen by top: top - 21:08:50 up 30 min, 10 users, load average: <strong>21.92</strong>, 16.95, 8.40 Tasks: 257…
Max Planck Institut für Astrophysik: The Millennium Simulation Project
, 1 min read
Article on Max Planck Institute Millenium Simulation. Pictures of the galaxy distribution Addendum: There is an article on the Millenium Simulation in Brian Koberlein's article Sim Universe.
Brian Koberlein on Google+: Astronomy Blog
, 1 min read
Brian Koberlein on Google+ on Astronomy (dead link) contains a number of interesting articles on current developments in astronomy and relativity. Added 31-Aug-2013: Brian Koberlein now has a WordPress powered separate web presence: www.briankoberlein.com. Added 21-Oct-2013: Brian Koberlein noted…
Counting to Ten on Linux
, 1 min read
Very good article by Bruce Dawson on timing CPU bound application. Results are: Using $(expr) to do math is over a hundred times slower than using bash internals. This is not a new discovery, but it’s worth reiterating. Excessive use of sub processes (see point 1) can confuse the Linux…
linux-3.8.4: Compile times
, 1 min read
In Phoronix Forum I have received feedback regarding the CPU time issue, as described below, see "CPU Usage Time Is Dependant on Load". Right now I use 3.2.0-38-generic #61-Ubuntu SMP Tue Feb 19 12:18:21 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux So maybe this behaviour is kernel dependant.…
Screenshots on Nexus 4 (Android 4.x)
, 1 min read
Press On/Off switch (right) and simultaneously press speaker volume button (left), voila, you've got your screenshot in Android. Here is an example from today.
Google Search says "Happy Birthday"
, 1 min read
Download "Sent Mail" from Google Mail via POP3
, 1 min read
It is easy to download received e-mail from GMail. It is not obvious how to download ones own sent mail. To do this you have to "Enable POP for all mail (even mail that's already been downloaded)" in the Setting's area, see picture below.
Fon and Deutsche Telekom Partner Together in Germany
, 1 min read
Yesterday Fon and Deutsche Telekom announced that Deutsche Telekom wants to partner with Fon. Fon already partnered with British Telecom, with Portuguese Zon, with Belgian Belgacom, French SFR, Croatian (Deutsche) Telekom, and others. Fon already partnered with E-Plus in Germany. But this…
GTC 2012 Keynote by Jen-Hsun Huang (Part 03): The NVIDIA Kepler GPU Architecture
, 1 min read
NVidia CEO Jen-Hsun Huang speaks on GTC (GPU Technology Conference (dead link)) 2012 on key differences between Fermi and Kepler. Key differences are SMX: Streaming Multiprocessor neXt generation Hyper-Q: keep GPU busy with queuing Dynamic Parallelism: GPU can now assign work to itself, e.g., run…
Possible Enhancements to J-Pilot
, 1 min read
Here are some thoughts about possible enhancements for J-Pilot. Convert pdb's and pc3's to SQLite. This makes it easier to analyze data according some criteria, e.g., find how many addresses have the same telephone numbers, how many entries in datebook contain the same substring, etc. Convert and…
Dead Keys and Compose Key
, 1 min read
My mother uses Xubuntu, i.e., she uses Xfce. She uses a German keyboard, but wants to write e-mails with spanish accents, i.e., she needs dead keys. At first I tried to solve the problem with a change in xorg.conf, which did not work. Some Google search revealed that a couple of people had the same…
jpilot-dump + jpilot-merge
, 1 min read
There is a lesser known command, jpilot-dump, to print portions of J-Pilot files. Here is an example to print category, first name, last name: jpilot-dump -A +A"%C %f %l" | less And here is another command: jpilot-merge.
ext3 vs. ext4
, 1 min read
Recently I installed an additional SATA drive on my Lenovo laptop. Without much ado I formatted the drive to ext4. Unfortunately, I quickly realized that the hard drive is spinning almost twice a second. My first drive on the laptop is also formatted with ext4, so using ext4 was a natural choice. A…
inotify-tools: inotifywait
, 1 min read
I wanted to see what files and when J-Pilot accesses its pdb and pc3 files. In my case strace produces much more output than actually needed. But inotifywait shows what and when files are accessed. inotifywait -m .jpilot/ inotifywait is in Debian/Ubuntu package inotify-tools. Here is an example…
OpenGL Program: Earth with Moon Rotating around Sun
, 1 min read
My other son had a practical training at Fraunhofer IGD. He wrote an OpenGL/C++ program in Windows where one views the earth rotating around the sun, thereby with its rotating moon, see picture below. openglSunEM-X I ported this program to Gtk/Linux. You'll find the code in openglSunEM.c. The link…
On Differential Forms
, 1 min read
A couple of years ago I went through Otto Forster's Analysis 3 book for self study of differential forms. I thought the presentation could be leaned more towards matrices and determinants, which since Bourbaki's time got a difficult stand in mathematics. Here is the document: On Differential…