THIS GUIDE IS DEPRECATED. Please read the explanation at the top of the Overview page.
To compare power usage of the boards I measured the amount of current drawn by each board as it sat idle, and as it ran the nbench benchmark tool. The data from this test can help describe the low and high range for power consumption from each board.
Current usage was measured using an INA219 breakout connected to an Arduino and measuring the current drawn to each board's 5V input (either through a barrel jack or USB micro B connector).
Each board was connected to a minimum of peripherals during the test. The Beaglebone Black, Raspberry Pi model B, and Intel Galileo were connected only to a network through their ethernet port. The Arduino Yun was connected to a network through WiFi. The Raspberry Pi model A was not connected to a network, and instead connected to a USB keyboard and HDMI monitor.
Current usage was measured using an INA219 breakout connected to an Arduino and measuring the current drawn to each board's 5V input (either through a barrel jack or USB micro B connector).
Each board was connected to a minimum of peripherals during the test. The Beaglebone Black, Raspberry Pi model B, and Intel Galileo were connected only to a network through their ethernet port. The Arduino Yun was connected to a network through WiFi. The Raspberry Pi model A was not connected to a network, and instead connected to a USB keyboard and HDMI monitor.
From the results above it's interesting to see the wide range in power usage. The Raspberry Pi model A is at the low end with ~150mA of average current draw. At the high end the Intel Galileo board consumes well over 500mA of current, even at idle! This large difference is likely a result of the difference in peripherals and supporting chips on each board. The Galileo has a lot of peripheral chips like an I/O extender, analog to digital converter, ethernet adapter, etc. which all consume power, whereas the model A board is just the Broadcom processor and very little else.
Both the Beaglebone Black and Raspberry Pi model B have similar power usage under load, but the Beaglebone Black is noticeably lower at idle. Even with its greater performance in the benchmark, the Beaglebone Black is slightly better at power usage than the Raspberry Pi model B.
Finally, it's interesting to see the impact of WiFi with the Arduino Yun results. While running over WiFi the Yun demonstrated low power usage compared to the other boards. To see how running other boards with WiFi would compare, I ran a quick test to measure the power consumption of the Raspberry Pi model A board at idle and under load with a small USB WiFi adapter connected. Power usage with the WiFi adapter increased by about 30-150mA, depending on network activity, which puts it in line with the Arduino Yun results. In general running a board with WiFi doesn't appear to be a dramatic cost in power usage.
Both the Beaglebone Black and Raspberry Pi model B have similar power usage under load, but the Beaglebone Black is noticeably lower at idle. Even with its greater performance in the benchmark, the Beaglebone Black is slightly better at power usage than the Raspberry Pi model B.
Finally, it's interesting to see the impact of WiFi with the Arduino Yun results. While running over WiFi the Yun demonstrated low power usage compared to the other boards. To see how running other boards with WiFi would compare, I ran a quick test to measure the power consumption of the Raspberry Pi model A board at idle and under load with a small USB WiFi adapter connected. Power usage with the WiFi adapter increased by about 30-150mA, depending on network activity, which puts it in line with the Arduino Yun results. In general running a board with WiFi doesn't appear to be a dramatic cost in power usage.
