Your top adsl speed is based up on different of factors.
Some of them are:
16 Mbps
ADSL
The maximum downstream throughput you can realistically expect from an ADSL connection at a distance of 17,000 feet from the Central Office (CO) is typically around 1 to 3 Mbps. ADSL technology experiences significant signal degradation over longer distances, and at this range, speeds can drop well below the theoretical maximum of 8 Mbps. Factors such as line quality and interference can further affect performance, leading to variable actual speeds.
11 Mbps
1 Gbps
132 Mb/sec
T1 line
45 Mb/s
1.5 Mbps www.intelletrace.com
d. 802.11n
802.11n.
Even a slow Ethernet network would be faster than ADSL, since 10baseT LAN networks run at 10 Mbps. An ADSL connection typically tops out at around 8 Mbps. However, if you are talking about throughput, then they might be very close, since Ethernet has problems with packet collision. Then again, most Ethernet networks today for LANs run at 100 Mbps, which would place it far faster than ADSL based on speed measurements. However, ADSL does not use the same transmission method as Ethernet, but Ethernet will still be faster than ADSL (especially if you consider the Gigabit speeds).