Slow Ethernet speeds??

OK I'm on 40Mbps fiber I receive to my PC via Ethernet around 38 ,
My ouya is now around 4" away from my router and I get 20Mbps wirelessly which I considered been fair because the ouya has a poor WiFi antenna setup and obviously its hardware is not brilliant but good enough
Now onto Ethernet , again same distance but using a 1.5m cat5 brand new out of the box I only get 17Mbps ,I know right WiFi on an ouya better than Ethernet wtf ?
So on my phone fair enough it has much better specs 2gb ram 8core 1.7 GHz processor I get around 30mbps sitting across the room using the same app ookla - speedtest .net on the same server
Could I just be asking to much of the ouya by expecting 30Mbps + via Ethernet because of its lack of processing power ?
I'm not hating it by any means but I'm sure you would be curios to why the speeds make no sence