Server connections speeds are a function of a variety of variables. The server’s connection speed to the Internet, all processes that are simultaneously trying to connect (uploads and downloads share the total speed available), the overall health of the Internet and the connection capability of the off-site computer, which is also limited by the same factors.
You can test the download speed of a Linux server by downloading a very large file and watching the speed.
# cd /tmp
# wget --output-document=/dev/null http://speedtest.wdc01.softlayer.com/downloads/test500.zip
# wget --output-document=/dev/null http://cachefly.cachefly.net/100mb.test