Tag: performance

• #Raspberry Pi 4B: Sometimes it's cool to be hot -or warm, to be exact ;)-

  Raspberry Pi | 6 min | 15093

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  performance

  raspberry pi 4b

  n-queens problem

  ice tower cooler

  heatsink

  temperature test

  This article is the last in a series of three articles that evaluates the performance of the Raspberry Pi 4B. This time the performance of Raspbian with standard kernel (4.19.y) will be evaluated with and without active cooling using two types of heatsinks. The other articles in the series are the following:

  1. The first article is about comparing the Raspberry Pi 4B and 3B+ performances:
     • Raspberry Pi 4B: How much faster is the new CPU?.
  2. The second article compares the Raspberry Pi 4B runn...

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• #Orange Pi Zero LTS: An 'upgraded' alternative to the old Raspberry Pis

  Product Reviews, Single-board Computers | 6 min | 36521

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  raspberry pi

  performance

  development boards

  n-queens problem

  armbian buster

  benchmark

  The Allwinner H2+, which integrates four ARM-Cortex A7 cores that can clock up to 1.2GHz, is powering the Orange Pi Zero LTS. The tiny board, which measures just 52 x 46 mm, features 802.11 b/g/n Wi-Fi, Ethernet, up to 512 MB of RAM, USB 2.0 Type-A and a microSD card slot. There is also a 26-pin unpopulated GPIO header along with a 13-pin header for a headphone, USB 2.0, TV-out, microphone and IR signals.

  This board is the next generation of the Orange Pi Zero th...

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• #Rock Pi S: a tinier version of the Raspberry Pi with Alexa functionalities

  Product Reviews, Single-board Computers | 6 min | 16110

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  performance

  development boards

  Rock Pi S

  Radxy

  OS image

  Alexa functionalities

  debian stretch

  Radxy, the company behind the Rock Pi 4 is back! A couple of days ago, I've received the Rock Pi S (see Fig. 1), a miniature developer board that measures just 38 x 38 mm. The board is powered by the Rockchip RK3308 SoC, which integrates four 64-bit ARM Cortex-A35 cores (Ultra-High-Efficiency). Each of the cores reaches up to 1.3 GHz. The SoC also has a built-in voice activity detector (VAD) for use with IoT and smart voice applications.

  Despite its tiny size, the Rock Pi S in...

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• #Raspberry Pi 4B: Real-Time System using Preempt-RT (kernel 4.19.y)

  Raspberry Pi, Real Time Systems | 7 min | 104544

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  preempt-rt kernel

  performance

  real time system

  raspberry pi 4b

  raspbian buster

  The Preempt-RT patching article is one of the most visited articles in my blog. However, that article needed a small update: Raspberry Pi 4B is out there and with Raspbian Buster, a new version of kernel is available: 4.19.y.

  I also uploaded the compiled and patched kernel to lemariva/RT-Tools-RPi. You can follow all these steps and compile the kernel by yourself or you can download the files from the repository and deploy the kernel on your Raspberry Pi 4B.

  This tutorial is the second of a...

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• #Raspberry Pi 4B: How much faster is the new CPU?

  Raspberry Pi | 4 min | 18676

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  raspbian

  performance

  raspberry pi 3 B plus

  jupyter

  raspberry pi 4b

  n-queens problem

  benchmark

  buster

  On July 4th, I ordered a Raspberry Pi 4B from Reichelt. On July 17th, I received the board, but it was broken, and a month later, finally I received a new board that seems to work OK :).

  The new Raspberry Pi 4B has a lot of upgrades and one of the most important ones is the RAM: You can choose between three models (1GB, 2GB and 4GB). But, another main change is the CPU and the RAM bus: they changed from a Cortex-A53 64-bit (3B+/3A+) to a Cortex-A72 64-bit, both ARMv8, and from LPDDR2 SDRAM...

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• #Raspberry Pi: The N-queens Problem (benchmark) Preempt-RT vs. Standard Kernel

  Real Time Systems | 5 min | 14954

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  raspberry pi

  preempt-rt

  standard kernel

  performance

  n-queen problem

  N-Queens Problem: A Benchmarking Solver for Raspberry Pi

  The N-Queens Problem/Puzzle is a well-known problem that consists of placing N chess queens on an N × N chessboard so that no two queens attack each other. For example, one possible solution to the N-queens problem for N = 4 is the following:

  Fig. 1: N-queens problem example (N = 4). Source: Google Optimization Tools

  As you can see, there aren't two queens on the same row, column or diagonal. Usually t...

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• #Raspberry PI Zero W: Preempt-RT Kernel Performance

  Real Time Systems | 2 min | 9334

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  preempt-rt

  performance

  standard

  kernel

  patching

  raspberry pi zero

  Today I patched the kernel of a Raspberry Pi Zero W with Preempt-RT. I used the repo TiejunChina.

  Update 18.03.2018: The official Preempt-RT patched Rasbian repo is here.

  ##~/rpi-kernel$ git clone https://github.com/TiejunChina/linux.git # update 18.03.2018: old repository##
  
  ~/rpi-kernel$ git clone https://github.com/raspberrypi/linux.git # update 18.03.2018: new repository
  ~/rpi-kernel$ cd linux
  ~/rpi-kernel/linux$ git checkout rpi-4.14.y-rt  # today the kernel version is 4.14.22
                                                  # with rt17 resulting in 4.14.22-rt17+ 

  You can find a complet...

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• #Raspberry Pi: Preempt-RT vs. Standard Kernel 4.14.y

  Real Time Systems | 5 min | 19927

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  raspberry pi

  kernel patching

  standard kernel

  preempt-rt kernel

  latency

  performance

  The last week I was working on a real-time application (with a 1 ms sample time) that runs on an ARMv8 Cortex-A53 (Raspberry Pi 3 Model B based board) and I was wondering the differences between latencies on the standard and the Real-Time (RT) Linux kernel. I had some problems with the standard kernel version, then I thought I could analyze the latencies of both kernels, and make some conclusions. Many test are available but with older kernel versions. The tests were perfo...

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