Podcast #128: We chat with Kent C Dodds about why he loves React and discuss what life was like in the dark days before Git. Listen now.
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Updated (much has changed): BogoMIPS is not useful for the new ondemand overclock config in raspi-config. It will provide 697 (which means 700MHz here) if you overclocked to 1GHz, because it is still in idle mode. 800 MHz are about 795.44 BogoMIPS . maximum CPU frequence (e.g. when your CPU is under load) sudo cat /sys/devices/system/cpu/cpu0/cpufreq/...


35

In benchmarking you must always establish what your limits are. Because if you expect to get 100mbs out of that lan than you are only fooling your self! Look at this Block design of the RaspberryPI Model-B So we establish a very important fact here. Ethernet is bottlenecked by the USB controller because form the block digram we establish it is connected to ...


33

First of all, remember that software for RaspberryPi is in early state of development and there are a lot of problems with it. They are worked on all the time but still, it's not yet as polished as it could be. Currently RaspberryPi is more oriented to developers than to normal users. It was never designed to be media center it just happens to be possible to ...


31

The license enables you to decode and encode (where applicable) the mentioned media types using the built in hardware encoders/decoders. H.264 Encode is enabled in the latest version (Included in Pi Price) which is great! For an extra £2.40 you can watch MPEG2 video, ie DVD's are encoded in MPEG2! For an extra £1.20 you can decode VC-1 video, ie ...


29

Without overvoltage (i.e. at the default 1.2V), most Pis can run at up to 800MHz stably. With overvoltage, 1000MHz is common. WARNING: Setting any of the parameters which over volt your Raspberry Pi will set a permanent bit within the SOC and your warranty is void. So If you care about the warranty do not adjust voltage. References: http://www....


28

I expect that, as Alex says, the benchmarks will show that the fastest Linux webservers will still be the fastest, regardless of architecture. If anyone wants to run benchmarks then the following tutorial has been useful to me: How to perform benchmarks on a web-server Serving Static Pages I have tested the RPi using Apache serving a simple static page: ...


25

As of April 2015 GStreamer 1.2 included in Raspbian supports OpenMAX hardware accelerated H.264 encoding through omxh264enc. I've done some benchmarking comparing: MacBook Pro (Early 2011) dual-core i7-2620M 2.7GHz (Sandy Bridge) - 4GB RAM RaspBerry Pi 2 Model B 900MHz quad-core ARM Cortex-A7 CPU - 1GB RAM Sample file: 60s sample from the movie Alatriste (...


24

You can perform a Raspberry PI stresstest with the sysbench tool. First example calculate primes sysbench --test=cpu --cpu-max-prime=20000 run Second example test the I/O Output of your Raspberry Pi sysbench --test=fileio --file-total-size=2G prepare sysbench --test=fileio --file-total-size=2G --file-test-mode=rndrw --init-rng=on --max-time=300 --max-...


22

If you are using recent version of Raspbian, it should already be enabled by default - as posted in the release notes here: http://www.raspberrypi.org/archives/1040 You can enable/disable L2 cache by using the disable_l2cache setting in /boot/config.txt. But before you rush there there's couple of things to consider: It's not free performance boost - you ...


22

Let's have a high-level overview of what an oscilloscope has: First we have the analog front-end. Here we have impedance-matching network for the probes (but the probes will have to have a capacitance matching part too), attenuation section (very important, so we don't overload the ADC or let high voltages in), triggering and connection to analog to digital ...


21

This is completely dependant on the Class of SD card you are using. A Class 4 card, which is the minimum recommended has an average read/write speed of 4 MB/sec. If you spend a little extra and buy a Class 10 card, you should find that the boot time is approximately 25% of the Class 4, as it should read at 10MB/sec. Using finnw's estimate that 24 seconds ...


21

Testing card read speed: There are two easy ways to test read speed (listing directory is only a read operation): using dd command: sudo dd if=/dev/mmcblk0 of=/dev/null bs=8M count=100 This will read 800MB of data from your SD card and discard this to /dev/null. If it takes to much time, you can change count=100 to count=10 to only read 80MB. After ...


20

I don't think you can change the default without recompiling the kernel. By that I mean, the one the kernel chooses when booted up. However, you can tell it to use a different governor while running, so if you want to effectively set the default without recompiling, you can add something to /etc/rc.local or some other start-up script. The /sys directory ...


17

Until 2014, the GPU firmware was closed source. OpenCL was not supported by the Pi until the VC4CL project, which has started to implement OpenCL on the VideoCore IV GPU used by all Pi models. The project's progress is also discussed on the Raspberry Pi Forums. See Can I use the GPU for calculations? for the state of the GPU as of 2012, but much has changed ...


15

You just need a video player that decodes the video using the GPU. The suggested (and currently the only known) player for the RPi that does this is OMXPlayer.


15

I timed it on my Pi, and it took 24 seconds from powerup to login prompt. This is with a Transcend Class 6 4GB SD card loaded with Debian Squeeze. This is the card that is recommended by RS for use with the RasPi, so this may qualify as "typical" as many users will probably have this type of card.


15

It's a combination of the Raspberry Pi's fairly weak ARM11 CPU and the unaccelerated X server. Since it's not accelerated by the GPU, the CPU has to do all the rendering; on something like the ARM11 core in the Pi, this puts a lot of extra strain on an already weak CPU. Anecdotally, while watching htop while Midori on the Pi loads a heavy website like ...


14

If you're going to have a HDD that's always attached to the Pi, then you can mount the sections of your filesystem that incur the largest number of read/writes directly from it. These directories are probably the culprits: /home/ /var/ /tmp/ You are able to mount partitions on your external hard drive to these directories automatically at boot. Let's say ...


14

This is already the correct answer IMO, and what I am suggesting will not probably not make much difference, but it might be useful to know. If all you want to do is run the browser, you don't have to run a desktop environment as well. Create a file which looks like this as $HOME/.xinitrc: #!/bin/sh midori If .xinitrc already exists, move it temporarily ...


13

cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq That will give you your current speed in kHz. Divide by 1000 to get MHz.


12

Certain things can be disabled that improve boot up speed - swap for instance (my Pi takes ages to activate it.) However, SD card reads are comparatively slow, and the device itself isn't all that fast - I don't think there's a magic bullet to make it boot up that much faster than by default. I know it's something you've considered already, but personally ...


12

The Raspberry Pi contains a /boot/config.txt. This file is read by the GPU before the ARM core is initialised. It can be used to set various system configuration parameters. Which can be used for overclocking. WARNING: Setting any of the following parameters which over volt your Raspberry Pi will set a permanent bit within the SOC and your warranty is ...


12

Change some of the preferences for Midori. The Midori preferences panel can be found at, Edit > Preferences The following preferences should have an effect on the speed of web browsing, Startup General > Startup > When Midori starts By default, Midori shows the last open tabs when it starts up. This can mean that you have to wait for the pages ...


12

Soon there will be a completely new alternative, Razdroid. It is Android 4 and already has a proven track record for embedded devices (Smartphones/ Google TV/ and posh toasters). A developer (Naren) from Braodcom is the main project contributor and in the final stages of porting Android 4 to the Raspberry Pi. {Community Mod- It would be great to embed a ...


12

For SD card performance it matters a lot whether the access is sequential (as with dd) or random access in small blocks. SD cards, especially those of high class seem to be optimized for sequential access, which is good for storing photographs or video. However, for running an OS of the SD card random access is more important, since lots of small files are ...


12

I run the RPi as my media station with Xbmc (now named Kodi) on Arch Linux. I have an external 1TB HDD (with external power supply) attached which holds my movie/series collection. Library Xbmc has Library features for Movies, Pictures, Series and Music with extended functionality (order by year, actor, whatever). But, before creating a library in Xbmc, ...


10

This caused some confusion for me as well and I spent some time spinning my wheels researching why web browsing in particular would receive such a great boost from hardware floating point operations as mentioned in raspberrypi's news. There is a misunderstanding among software developers that the area of silicon in your computer dedicated to doing floating ...


10

To get the best speed out of your MacBook's SD slot, you need to use a 'raw disk' device. This is a SanDisk Ultra Class 10 card: ~/Desktop/rpi $ sudo dd if=2012-12-16-wheezy-raspbian.img of=/dev/disk1 bs=8m 231+1 records in 231+1 records out 1939865600 bytes transferred in 1076.078932 secs (1802717 bytes/sec) Compare this to using /dev/rdisk1 instead of /...


10

I am assuming you are using server side driver ie. have the CUPS use the Samsung driver. You might be able to speed up the printing process by making the printer a RAW printer.DO this by selecting the Printer model as RAW when selecting the printer and installing the drivers on the computer.This will reduce the CPU load significantly. However setting the ...


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