As an experiment I setup a Raspberry Pi Zero W with the GS hub and three R606's.
After a full day the hash rate on all three match the Pi 3b+ speed which is 900Gh.  These are also the numbers I saw on a Windows 10 PC.
Next is the TinkerBoard but it will probably just be the same. 

I think the only two constraints (as others have mentioned) are the USB traffic and the possibly the network connection.
The fact that it worked at all with the Pi Zero was surprising let alone at the same speed.