There are configuration issues relating to your NIC (Network Interface Card) that may be part of the problem... I experienced substantialy better performance when I used the tools located at
DSLReports.com see the item called Tweak test. Also the Speed Test item can give you an idea how your connection is performing in general.

Beyond that the ISP network managment could be an issue... cable modems are on Ethernet segments... basicly subscribers are grouped into segments... if too many subscribers are lumped on the same segment (think party-line) performance can be severly impaired. It could be you and your friend are on different segments ... and your segment is overloaded.

As with everything on the internet the slowest point between you and the other end will be the limiting factor ... regardless of the connection you may have.