Testing the Odroid-C2 and LeMaker Guitar

Odroid-C2: The Little Black Board

The Odroid-C2 sits on a very new ARM Cortex-A53 processor, which runs a 64-bit Linux kernel. The quad-core Odroid comes with 2GB of RAM and an AMLogic S905 CPU. Otherwise, the equipment is substantially similar to the Raspberry Pi 2 (RPi2). The C2 also has four USB 2.0 ports but no WiFi and Bluetooth components. You will, however, find support for Gigabit Ethernet connections. The C2 costs $40 on the Hardkernel website [4] and £44 or EUR50 if purchased in Europe. The 8GB eMMC module for Linux or Android costs $18 (£19, EUR24).

The C2 board (Figure 2) is comparable in size to the Raspberry Pi. However, the appearance of the two boards is very different. The C2 is black in color and has a heat sink, which takes up a healthy one third of the front side. The microSD card slot looks unusual because it is not actually a slot. Instead, it consists of a small jack on the reverse side (Figure 3). This comes across as perhaps an overly adventuresome feature, but it presents no problems in testing. The card remained securely in place. If desired, you can accessorize the C2 with an eMMC flash module.

Figure 2: The small, robust Odroid-C2 is about the size of a Raspberry Pi.

Figure 3: The microSD card port on the Odroid-C2 is actually more of a jack than a slot.

The 40-pin GPIO bar is not fully compatible with the Raspberry Pi. This lack of compatibility is due to the ADC inputs on the hardware. Power is delivered either via a micro-USB connection or via a distinctive jack plug.

Currently Hardkernel only offers Android operating systems and an Ubuntu variant for the Odroid-C2. The little computer ran smoothly during testing under Ubuntu. Nonetheless, the manufacturer takes it upon itself to address a series of problems, such as the ongoing lack of graphics support under Linux. Additionally, not all software harmonizes with the AArch64 kernel for 64-bit processors.

Graphics support is supposed to accompany the upcoming switch to a Linux kernel of the 4.x series. The efforts needed to create the support should sequence directly into the mainline branch of the kernel, thus avoiding an isolated application. These plans for the future make it clear that the user currently has to use Android to have the popular 4K resolution, as well as video decoding with H.265. Although Kodi starts on the Odroid-C2, it does not work.

The Champion

Performance tests for the Odroid-C2 and the LeMaker Guitar comprised the Sysbench and UnixBench benchmarking tools. The results are shown in Table 1. The performance of the AArch64 Linux architecture on the Cortex-A53 was impressive.

The Odroid surpasses even the leading LeMaker HiKey with its eight cores, and it distinguishes itself as the clear winner when compared with the Guitar. The large heat sink performs well, and the processor did not exceed 40C (104F) during testing. The fan that comes with the larger Odroid-XU4 model is not necessary.

The LeMaker Guitar gains only a minimal advantage during the CPU test with the Sysbench benchmark. With the UnixBench benchmark, the CPU performance is less than that of the Raspberry Pi (Figure 4). However, the user typically won't notice any difference with desktop applications, because the Guitar's faster eMMC memory outperforms the Raspberry Pi's SD card.

Figure 4: The Odroid-C2 emerges from the tests as the winner. The LeMaker Guitar, on the other hand, runs behind the Raspberry Pi on the UnixBench tests.

According to instructions provided in the manual, the user will explicitly have to overclock to 1.3GHz for the Guitar to reach the benchmark values. The computer does reach temperatures of up to 68C (154F) under this kind of heavy load. Even so, the Guitar continues to run smoothly. If placed inside a cover, this clock rate and the resultant heat may lead to problems.

The LeMaker Guitar and the Odroid-C2 are also different in terms of energy consumption. The Guitar needs 670mA with 9V. The C2 gets by with 660mA and 5V. The difference in needs is due in part to the Guitar WiFi module, which eats power.

Both computers have decent Internet speed. During testing with iPerf, the Odroid-C2 reached a throughput rate of 939Mbps with its Gigabit connection. The LeMaker Guitar only achieved 79.5Mbps with its Fast Ethernet connection. However, when using WiFi, the Guitar gets up to 48.7Mbps and even beats the RPi3 at 45Mbps.