FWIW...my Odroid N2 only has USB 3.0 ports on it and I can crank my Newpacs and R606 to the moon on it using the Gekko USB hub. Never once had an issue pop up and have run my 606 all the way up to 775MHz for a few days without cgminer tuning it down.
I'm currently running the R606 at 700MHz and 2 Newpacs at 500MHz. WU is at 100%.
Like @DieselWeaseI, my Odroid N2 has been running flawlessly for three weeks, but with three R606s instead of one -- mine are trying to run @575MHz though, and all at 100% WU. The first R606 can only do 538 MHz @ Volt setting 4, the other two run @ 575 Mhz -- no problem. The Odroid N2 has six cores (4x1.8 and 2x1.9) and 4Gb of ram -- very nice little SBC running Ubuntu Mint.