internet speed

Are you looking for sympathy or help? If the latter please confirm that the speedtest is with one late model computer connected by ethernet directly to the modem and specify the service used for the speedtest. Also tell us the brand and model of the modem.

 

Are these new machine or are they older which means they may have slow (10,100) network cards, that do not support the faster speeds?

This Draytek router, is it of the High speed type or the older slow 10,100 type?
Model number of it may help us?

 

Since you mention a radio antenna I assume that your point to point is wireless. A lot (distance; interference; antennas not oriented perfectly) can lessen the bandwidth, so I cannot venture an opinion about whether you are getting as much bandwidth as possible for your location.

Regardless of type of internet service your best (most reliable) speed test will involve as few devices as possible. So, you should be concerned about the speed with one computer connected by ethernet and with no other devices using the network.

10/100 Mbps ethernet devices can handle speeds greater than 50 Mbps.