Getting a max 15MB/sec write speed on my PR4100, How to improve?

I got a PR4100 connected via link aggregation (Both ports) to a Netgear R8500. I´ve selected then network Link Aggregation to 802.3ad and its supossed active the link agregation.

However when copying to my PR4100 i get writte speeds of 15MB/sec meximun. I should be getting above 100MB/sec aint it?

What could be wrong? Im connected via wireless on 5GHZ network

What device are you copying from? A (gigabit) computer? A hard drive with USB 2 connection or USB 3? Through a gigabit router and/or gigabit switch?

I have WIRED gigabit “everything” in the chain and USB 3 drive attached to PC, and I get over 100MB/sec under these conditions.