Downld speeds depend on the sources generally.
See the following link & follow all the off-shoot links to find hints & extra skills to help in your quest: To continue files downlding (click on link)

For a 512 kbps connection your max downld speed capacity would be around 50 KB/s depending on how far you are from the phone exchange. 90 kbps = 11.25 KB/s

Don't get confused between bits & bytes. 8 bits = 1 byte.

512 kbps(kilo bits per second) = 512/8 - overhead loss = approx 50 KB/s (kilo bytes per second)

LW measures speeds in KB/s whereas some other p2p share programs use kbps!