Kepler’s Hypothesis explained by Brian Koberlein

16th June 2013

I copy Brian Koberlein's explanations in Google+ on the history of Kepler's law. Kepler’s first two rules, that the orbit of a planet is an ellipse, and that a line drawn from the Sun to a planet sweeps out area at a constant rate were proposed in 1609. While these rules allowed for a more…

Running CPU/GPU Intensive Jobs on Titan Supercomputer

16th June 2013

There is a an INCITE program (HPC Call for Proposals), where one can apply for CPU/GPU intensive jobs, the link is INCITE. From the FAQ: The INCITE program is open to US- and non-US-based researchers and research organizations needing large allocations of computer time, supporting resources, and…

Positive Erfahrungen mit Unitymedia

15th June 2013

Bisher habe ich mit der Firma Unitymedia ausschließlich positive Erfahrungen gemacht. Sie sind es wert, kurz festgehalten zu werden. Am 20. August 2009 habe ich bei Unitymedia Internet (20MBit/s) und Telefon bestellt. Am nächsten Tag stand ein Herr Niclas Roth von Computer-Füchse vor der Tür…

Cisco Cablemodem Signal to Noise Ratio

14th June 2013

For internet connection I use a cable modem EPC3208 from Cisco, which was supplied by the cable provider, Unitymedia in my case. It shows the following measurements regarding signal-to-noise ratio, modem is at More information on this modem can be found here: Cisco EPC3208 (dead…

Mainframe Rehosting: Cost Reduction, Hardware Sizing, Tools, and Methodology

9th June 2013

Mainframe rehosting is about replacing the whole mainframe with one or multiple Linux boxes, or at times, move portions of the application landscape from the mainframe to Linux. Thereby you basically keep many of the hitherto used development- and runtime-environment, like COBOL, DB2, IMS, CICS,…

WordPress March 2009 Wrap-Up

4th June 2013

Impressive numbers from 827 terabytes of data, 400.000 new users, 7 million logins, 1 billion of pageviews. From March Wrap-Up, written by Matt Mullenweg: In March we brought you P2, an awesome theme perfect for short-form and group blogging, made with love by Automatticians. Next,…

Vasily Volkov (UC Berkeley): Unrolling parallel loops

1st June 2013

Loop unrolling is not only good for sequential programming, it has similar dramatic effects in highly parallel codes as well, see Unrolling parallel loops (local copy), also see #pragma unroll in the NVidia CUDA programming guide. Some bullet points of the presentation: More resources consumed per…

WordPress Statistics of this Blog: Top Views by Country

31st May 2013

How to use TrueType Fonts in xterm or uxterm

29th May 2013

See how to use ttf fonts in xterm in the NetBSD tutorial. To get TrueType fonts by default in uxterm or xterm I added the following lines in .Xdefaults: XTerm*faceName: Bitstream Vera Serif Mono XTerm*faceSize: 14 UXTerm*faceName: Bitstream Vera Serif Mono UXTerm*faceSize: 14 It didn't work if I…

The New Digital Company: Distributed, Online, and Transparent

21st May 2013

Very good article on open company communication by Sara Rosso, who works for WordPress. The article below centers around these headlines. Be distributed Be Online Be Transparent Work Hard, Play Hard When I Have Time by Sara Rosso Update: I gave a similar presentation at LeWeb about the Future…

CUDA without X Window System

16th May 2013

Instead of starting X like xinit /usr/bin/icewm and therefore loading the NVidia CUDA environment, one can simply add [ -c /dev/nvidia0 ] || mknod -m 666 /dev/nvidia0 c 195 0 [ -c /dev/nvidiactl ] || mknod -m 666 /dev/nvidiactl c 195 255 to /etc/init.d/boinc-client assuming one has a single…

Porting Source to Linux - Valve's Lessons Learned

15th May 2013

Interesting slides from Valve on their venture to Linux: Porting Source to Linux - Valve's Lessons Learned

John Raff / Dmitry Sandalov: Access Google translate from a terminal

6th May 2013

See an article by a guy named johnraff, Access Google translate from a terminal, or reblogged by Dmitry Sandalov here Access Google translate from a terminal. Works great. Here are some examples: translate Weg Way translate "Ich gehe nach Hause" I'm going home

Phoronix: NVIDIA vs. Nouveau Drivers On Ubuntu 13.04

5th May 2013

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

1st May 2013

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

30th April 2013

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

30th April 2013

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

27th April 2013

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

27th April 2013

Brian Koberlein on Google+ on Astronomy contains a number of interesting articles on current developments in astronomy and relativity. Brian Koberlein on Google+ Added 31-Aug-2013: Brian Koberlein now has a WordPress powered separate web presence: Added 21-Oct-2013: Brian…

Counting to Ten on Linux

21st April 2013

Very good article on timing CPU bound application.