This is a comparison of two Linux embedded boards the first one is the Arietta G25 board made by Acmesystems and the other is the WiFiG25 board made by Core Wind tech. Both boards are powered by the Atmel AT91SAM9G25, this is an ARM9 SoC processor clocked at 400Mhz with a bunch of features that include full speed USB host and device, SDCard interfaces, USARTs, SPIs, I2C, 10-bit ADC, several GPIO pins, support for DDR2 RAM and others.
One of the advantages of these modules is the small size, the amount of peripherals they have and the fact that they run Linux. Both boards need 5VDC for supply via a micro USB connector but the IO level is 3.3 VDC. They can be used for robots, control projects or as a small gateway server for IoT applications.
Since both are powered by the same processor it is possible to interchange the SD card with the OS from each other, for this comparison an SD card with a Linux 4.4.1 kernel was used. One precaution that has to be taken into consideration is that although both boards have an external 40 pin connector the pin-out of each board is completely different and some ports such as SPI or I2C are mapped to different pins on the external connector. For a full description of the pin-outs of each board you can check the Arietta G25 and the WiFIG25 webpages.
In terms of support and documentation both boards have a lot of guides and tutorials but I personally prefer the documentation for the Arietta board, it is possible to find what you need in a very easy and fast way also the tutorials are clear and well explained. The good thing is both documentations are almost interchangeable so find the one you like more and follow it as you need.
The features of each board tested for this review are as follow:
|Size||53 x 25 mm||50 x 30 mm|
|RAM||256 Mb||128 Mb|
|Flash||None||256 Mb NAND Flash|
|WiFi||External module (not included in price)||On board Module with internal antenna|
|List price:||US$ 33.46* (30€)||US$ 29.90|
|Shipping:**||US$ 17.85* (16€)||US$ 20.00|
|Total cost of system:||US$ 62.61* (56.12€)||US$ 49.90|
* Exchange rate: 1EUR=1.1157 US$
**Shipping cost to UK
***22% VAT included
To test the performance of the boards UnixBench benchmark has been installed and ran on the boards to compare the performance of both. The purpose of UnixBench is to provide a basic indicator of the performance of a Unix-like system.
To install and run this program on the boards you need to connect them to the internet and run the following commands:
apt-get install perl perl-modules make
After installing these packages you can download the latest version of UnixBench from google code with the following command:
wget http://byte-unixbench.googlecode.com/files/UnixBench5.1.3.tgz tar xvf UnixBench5.1.3.tar.gz
To run the benchmark just cd into the folder and run as follows:
cd UnixBench5.1.3 ./Run
After typing the running command you will see the tests that are being conducted by the benchmark.
The UnixBench results obtained by the AriettaG25 board are:
The UnixBench results obtained by the WiFiG25 board are:
As you can see from the results both boards are similar in performance, the scores for processing tasks are the same and the ones with small differences are because of the different memory chips used on each board. Based on these small differences would be possible to conclude that the performance is the same.
To have a perspective on the UnixBench results obtained by the AT91SAM9G25 powered boards bellow is a table comparing them with results of other boards and processors (more is better):
|Board/Processor||System Benchmarks Index Score|
|Arietta G25 (256Mb RAM, 1 Core @ 400MHz ARM)||32.6|
|WiFiG25 (128Mb RAM, 1 Core @ 400MHz ARM)||32.8|
|Raspberry Pi (1 core @ 700MHz ARM)||109.8|
|Raspberry Pi 2 (4 cores @ 900MHz ARM)||432.2|
|AMD Sempron(tm) Processor 3400+ (1 core @ 2 GHz x86)||555.1|
|Odroid-U2 (4 cores @ 1.7 GHz ARM)||806.6|
|Intel Core i3 (4 cores @ 2.20 GHz x86)||1701.4|
|Intel Core i7-3610QM(4 cores @ 2.3GHz x86)
(My PC running Linux Mint 17.2)
The capabilities and cost of both boards are similar although the Arietta has no internal Flash and if you want to connect it to a WiFi network an external module is required and that adds to the cost. Another aspect to take into consideration is that now both boards can be replaced by the Raspberry Pi Zero that cost a fraction of these boards and based on the UnixBench benchmark results the Zero offers much more performance in comparison (the Zero is based on the Raspberry Pi 1) .