Mining Litecoins: ZedBoard or Raspberry Pi?

Recently, there has been a lot of talks on Bitcoins and other crypto currencies, which are rapidly gaining awareness and acceptance in a number of areas. Having recently read a very interesting article in the latest Xcell Journal on using the Zynq All Programmable SoC to mine Bitcoins, I thought I would have a look at how the Zynq-based ZedBoard and the Raspberry Pi performed when mining Litecoins (LTCs or sometimes XLTs), which are an adaption of Bitcoins.

Now, I must admit straight off that using only the CPU on both of these systems (as opposed to offloading some of the processing to programmable FPGA fabric) will take a considerably long time to generate a Litecoin. Since I had both boards available, however, I thought it would be a fun little experiment to determine their hash rates.

In order to provide the best comparison, I used the same mining programme, cpuminer, on both the Zynq and the Rapsberry PI. I also ran them both from the command-line (as opposed to a GUI) so as to ensure optimal performance.

In the case of the Zynq, I installed Xillinux on a SD card for the ZedBoard before installing the mining programme. By comparison, the Raspberry Pi already came with a Linux distribution, so all I had to do was install the mining programme.

Both the Raspberry Pi and the Zynq contain ARM processors—the ARM11 in the case of the Raspberry Pi and dual Cortex-A9 processors in the case of the Zynq. The ARM11 is capable of 1.2 DMIPS/MHz, which—operating at 700MHz, as the Pi does—gives 840 DMIPS. Meanwhile, the Cortex-A9 is capable of 2.5 DMIPS/MHz. Since the Zynq on my ZedBoad is running at 666MHz, this means that each processor on the Zynq provides a maximum of 1,665 DMIPS (nearly double that of the Pi for each of the Zynq's processors).

Once the mining program has been launched on the ZedBoard, the Zynq implementation of Xilinux uses the OLED display on the ZedBoard to show the loading on the processors and SD card. During the mining operation, the load on the SD card is low, but the processors are heavily loaded.