If it's genuinely a hub not a switch - as it appears to be - then it is half-duplex. Only one device can be transmitting at any time, just like a wireless network, or homeplug extenders.
It's therefore impossible to transfer at more than 10Mbps, and the typical achievable throughput I would expect would be more like 4Mbps.
If you're seeing faster speeds than this, then I have to ask, how are you measuring those speeds? Most likely it's an artefact of the testing software, e.g. it's stuffing data into buffers and counting this as "sent" even before it's actually gone out of the NIC. This varies with different test sites, but people have reported that fast.com is particularly prone to this problem, reporting speeds like 1.5Gbps on a gigabit connection.
The only other possibility would be if it's a 10/100 hub (those were rare beasts!) and so you're running 100M half-duplex.
You should be able to check with your NIC status what speed has been negotiated. At least, under Linux you can do this with ethtool. I have no idea how you'd do it with DOS 6.22
Print Thread
