blaktro

I just found out B9 tv has only 100mbps ethernet, even tho it should give me at least 80mbps download speed rate. My download speeds are between 15-20mbps and I dont know why. I pluged in laptop with 100mpbs ethernet network card in the same UTP cable, and it goes to 80mbps at speedtest.net. (my ISP speeds are 300mbps download, 25 upload) I use PLEX and the speed does matter. Can you tell me what may be the problem, what can I make to solve it?