DSL stands for Digital Subscriber Line, and it comes through the phone line. Therefore you are connected through your personal line all the way to the source where the line originates. As a result the DSL Bandwidth speed is stable.
Internet Cable is fed to the system by nodes, which are sort of halfway points between you and the source. The Internet Service Provider (ISP) provides a bandwidth to an area that includes many customers, and they share the bandwidth. As a result, during peak usage the speed can be significantly degraded.
Which is better and/or faster is hotly debated, and ultimately it depends on what is available in your area. While DSL offers users a choice of speeds ranging from 144 Kbps to 1.5Mbps, cable modem download speeds are typically up to 2 times faster than that, BUT because cable technology is based on shared bandwidth, the speed fluctuates.
In more rural areas with fewer subscribers, you’re bound to have faster download speeds than a subscriber in a metropolitan center.
On the upload stream, however, cable and DSL are closely matched for speed. Both DSL and cable Internet speeds are largely dependent upon the service provider and either the distance away from the switching station you are or how many subscribers are in your immediate area.
If you’re thinking of switching from one to the other, testing your current connection’s internet speed over a period of time can help you decide, especially if you can compare them to others in your area. If you haven’t decided which service is best for you, ask your neighbors which service they use, what speeds they are getting, and if they’re having any problems. Then break down the speed versus the cost, and decide which works best for you.