You can check your dedicated server port speed by running the following commands in ssh:
1) /sbin/ethtool eth0 - you'll see something like this
Supported link modes: 10baseT/Half 10baseT/Full
2) dmesg | grep -i eth - you will see somthing like this
tg3: eth0: Link is up at 1000 Mbps, full duplex.
tg3: eth0: Flow control is off for TX and off for RX.
You can have upload/download test as per this article.