April 14, 2017

Odroid XU4

This is a looser due to the docs being unavailable from Samsung, but take a look at the Odroid C2 (below) before you give up entirely.

The Odroid XU4 is based on the Samsung Exynos5422 with Cortex-A15 2Ghz and Cortex™-A7 Octa core CPUs. So this has 8 cores of two different flavors. The Cortex-A15 is a high performance 32 bit core and the Cortex-A7 is the good old 32 bit core we know and love from the Beaglebone.

But never mind this board for now. No user manual is publicly available. Supposedly you can negotiate an arrangement and sign an NDA to get it, but reports are that requests of this sort have been denied. Most likely you need to be a corporation and have your lawyers talk to their lawyers.

Or mind it if you want. If you can make do with the linux provided by the board vendor, this could work for you. Do you want 8 cores like this or 4 of the 64 bit cores in the Odroid C2? One thing I don't like about the XU4 is that it has a fan. So unless you need all those cores and the fast A15, go with the C2. The following article has ratings based on the Dhrystone benchmark. It seems to say that the A53 doesn't perform much better than the A7 or A8, but the A15 is a significantly better performer than any of those.

Odroid C2

As an alternative to the Orange Pi (or Raspberry Pi for that matter), consider the Odroid boards, in particular the Odroid C2. It is based on the AmLogic S905 SoC, which is a device built for set top boxes, much like the Allwinner H3 and H5 in the Orange Pi boards. More like the H5 because it has a quad core 64 bit ARM A53.

Some notable features:

In particular the ethernet is part of the SoC, rather than hooked on via USB like the wretched situation with the RaspBerry Pi. Onboard eMMC will always be significantly faster than running from an SD card. It looks like it has a pair of i2c interfaces, which is a plus over the Allwinner H5. Some overoptimistic early advertising claimed a 2GHz clock, but it really runs at 1.5 Ghz.

Direct sales by Hardkernel shows a $46 price.

Buying it from Amazon you pay $70.

Either way, it comes with no eMMC and you buy a separate "eMMC module". these are listed as "accessories" and sell for the following prices: 

 8GB eMMC Module C2 Android Black	$16.50
16GB eMMC Module C2 Android Black	$24.50
32GB eMMC Module C2 Android Black	$37.50
64GB eMMC Module C2 Android Black	$57.50
128GB eMMC Module C2 Android Black	$76.50
You can order them preloaded with Linux or Android (your choice) for the same price. It is not clear if the 128G module will or will not work on the C2 board. (Not that I care, I would buy the 8G module).

They also sell an eMMC "programming adapter" that looks like it would let you plug a module into an SD card reader. This is inexpensive ($1.50) so definitely get one.

Note the heat sink on the board. They offer a 5 volt 4 amp (!!) power supply, and mention that the device will pull 1.2 amps at least.

Have any comments? Questions? Drop me a line!

Tom's electronics pages / tom@mmto.org