The WiFi situation is indeed annoying and I've complained about it, they seem to be since looking into it, but as the driver is open source, someone else could check too and send patches. There even is a debug tool to intercept the proprietary QC driver commands (used in Android images). It should just be reconfiguring the filters away from their broken default state.
[0]https://www.apm.com/products/data-center/x-gene-family/x-c1-...
Largely, the hardware and firmware bugs have now all been resolved or worked around.
Downsides: No wake-on-LAN. No IPMI. (Both rumoured to exist in the management core, but I've not worked out how to enable either). The 10 Gb ethernet doesn't work for me. I don't have a monitor plugged into mine, but that's OK since I only care about serial access for ARM server hardware. Mine is noisy because of the numerous, loud fans. I disabled all the case fans, but haven't had the balls to disable the processor fan which still makes a racket.
For virt development, OpenStack and that kind of thing, they're the only [aarch64] game in town.
In summary, they work well.
Edit: Their site and sales sheet have a discrepancy about power supply. Does the dev kit come with one, and what are the specs? Thanks again!
The machine is physically a standard 19" 1U rack case, half depth (or less?). It comes with an 80W PSU and a single SATA HDD. I fitted mine with a second SDD (I believe there are 4 SATA ports on the motherboard, but not enough room in the case for 4 hard drives).
The motherboard inside is pretty tiny, about 7"x7".
Red Hat have some Caviums and Seattles as well, but I've not used those.
Edit: I forgot an important point: The upstream kernel works out of the box. (For x86 users, this will sound like a strange thing to point out, but it's BIG news in the ARM world).
Idle, text 1W 5VA
Idle, X 2W 5VA
1CPU, X 3W 7VA
2CPU, X 4W 9VA
4CPU, X 4W 11VA
(CPU load generated by dieharder statistical randomness test on AES_OFB CRNG, dieharder -a -g 205)Incidentally, Dieharder's AES_OFB CRNG (which I don't think uses the AES instruction set on intel) runs at 5e6 randoms per second per thread on dragonboard, compared to 2.5e7 randoms per second per thread on my 3yo 2-core/4-thread i5 laptop at 2.6GHz, to make just one simplistic comparison of CPU speed.
(edited to try to fix formatting)
Not publishing the schematics and a couple of other things are actually violating the grand LINARO 96boards compliance spec, but nobody there seems to really give a f...art.
Idle, text 15.2v 115mA 1.75W
Idle, X 15.2v 124mA 1.89W
1CPU, X 15.2v ~180mA 2.74W
2CPU, X 15.2v ~240mA 3.65W
4CPU, X 15.2v ~260mA 3.95W
All of my CPU loading scenarios had much more variable current readings, I tried to record the highest value I saw on a multimeter with a ~.5s update time over 10+ seconds.
On the other hand, it did work well enough for me to make a basic port of LinuxCNC to it, though without a working PREEMPT-RT kernel it cannot be used to control hardware.
Of the ARM SBCs I own, this board is way below ODROID U3 and RPi2 -- it's buggy, it's not particularly high spec (other than being aarch64), and it doesn't have the world of accessories that RPi has. (Pick ODROID for performance, RPi for accessories)
But if you want to port an app to aarch64, or just say that you own a 64-bit arm system, and your hardware budget is under $200, DragonBoard and hikey are basically the two games in town.