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In Hard-Disk and SSD Speed Comparisons I compared a Mushkin SSD with 60 GB against a ADATA with 128 GB against a Seagate 1 TB hard disk drive. The SSD's had roughly three times the speed of the hard disk drive. I.e., 380 MB/s vs. 134 MB/s for reading Mushkin vs. Seagate, and 297 MB/s vs. 131 MB/s…
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At times WordPress.com uses its user base to experiment with some half baked new features, see for example Classical editor in WordPress.com, or see this Hello Jekyll, bye Wordpress.com! These are the times when I consider migrating from WordPress.com to another blogging platform. Usually after…
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This post is about the Microsoft Exchange GAL, i.e., the global address list. The task is to export the data in the GAL to vCard format. Microsoft Outlook stores local caches of the GAL in %userprofile%\Local Settings\Application Data\Microsoft\Outlook, see Administering the offline address book in…
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In Effect of Optimizer in gcc on Intel/AMD and Power8 I measured speed ratios between optimized and non-optimized C code of three on Intel/AMD, and eight on Power8 (PowerPC) for integer calculations. For floating-point calculations the factors were two and three, respectively. Michael Larabel in…
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In Downloading Binary Data, for example Boost C++ Library I already complained about some company policies regarding the transfer of binary data. If the openssl command is available on the receiving end, then things are pretty straightforard as the aforementioned link shows, in particular you then…
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After upgrading to Google Chrome version 50 I could hear sound in YouTube videos, but no images/video. At first I thought this was a matter just affecting me. Now I noticed that another machine which I upgraded to Google Chrome v50 also lost the ability to watch video in YouTube. This other machine…
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This short guide describes how to upgrade your OnePlus One Smartphone from OxygenOS version 1.0.3 to 2.1.4. In this case the initial version of your OS is of no relevant importance -- you can also upgrade from version 1.0.0, but see Installing OxygenOS 1.0 on the OnePlus One Smartphone and…
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Ico Doornekamp on 20-Dec-2011 asked why a C version of a Lua program ran more slowly than the Lua program. The mentioned discrepancy cannot be reproduced, neither on an AMD FX-8120, nor an Intel i5-4250U processor. Generally a C version program is expected to be faster than a Lua program. Here is…
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Christian Terboven and Dirk Schmidl from IT Center RWTH Aachen presented a deck of slides on OpenMP: Introduction to OpenMP OpenMP Tasking In Depth OpenMP Recap OpenMP and Performance Advanced OpenMP Features Some very striking slides are reproduced here. Not directly related to OpenMP but…
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I recently read in Computers are fast! by Julia Evans about a comparison between fread() and mmap() suggesting that both calls deliver roughly the same performance. Unfortunately the codes mentioned there and referenced in bytesum.c for fread() and bytesum_mmap.c for mmap() do not really compare…
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This blog was viewed more than 30.000 times. As in this post, here are the numbers: The averages per day are: The development of visits is as below: Top posts (all time) are: Most visits come from US and Germany by a wide margin:
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See the fireworks Elmar Klausmeier's Weblog created by blogging on WordPress.com. Check out their 2015 annual report. Here is an excerpt: The concert hall at the Sydney Opera House holds 2,700 people. This blog was viewed about 14,000 times in 2015. If it were a concert at Sydney Opera House, it…
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Today I received an invite for the OnePlus X. The code is: GL71-90E4-75E1-DBA7. This invite is valid for 3 days.
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I got above error message in nginx. Stackoverflow post 413 Request Entity Too Large - File Upload Issue had all information to resolve the issue. The solution was written by User Arun. One has to edit /etc/nginx/nginx.conf and add in http{...} client_max_body_size 15900M ; and /etc/php/php.ini ;…
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Below is a short overview of small scale computers for use in embedded computing. Intel Galileo, single core Quark/Pentium, ca. 100 USD, <15 W Intel Edison, dual core Atom Silvermont, 500 MHz, ca. 100 USD, <1 W Raspberry Pi, single core ARM, 700 MHz, ca. 35 USD, ~1 W Arduino series, e.g.,…
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I had to detect Windows junctions (similar but not identical to symbolic links) in Python. On stackoverflow.com I read the following Python code given by a user named eryksun for handling them, as os.islink() does not work for junctions. The routines access Windows functions CreateFileW(),…
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Brian Koberlein mentioned that NASA provided photos from Apollo moon mission on Flickr.com. Below is one:
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Advertisements on web-pages is ubiquitous. Without advertisement even this blog could not be offered free of charge. But advertisement can be a real nuisance with its blinking, flickering, moving, and distracting appearance. Sometimes they even contain malware. There are two simple remedies for…
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I upgraded my OnePlus One smartphone from Oxygen 1.0.0 to 1.0.3, see Installing OxygenOS 1.0 on the OnePlus One Smartphone. Download OxygenOS 1.0.3 from OxygenOS 1.0.3 with the latest Stagefright patches, and check MD5. Then upload the zip-file. adb push ~/Download/ONE_12_A.01_150827.zip…
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I learned the hard way that a user in /etc/passwd not having a shell specified in /etc/shells is not able to log-on. On Ubuntu /etc/shells looks like this: /bin/sh /bin/dash /bin/bash /bin/rbash /usr/bin/tmux /usr/bin/screen On Arch it looks like this: /bin/sh /bin/bash So if you provide a user…