How to Compare PCI Modems and DSL Cable Modems

Step 1

Check the connection type on the modem. The modem is a cable modem if it has a coaxial cable connection that is identical to one used for cable connections on a TV. The modem is either a DSL modem or a PCI modem if it has a phone line jack. DSL modems also have one or more Ethernet jacks, which look like extra-wide phone jacks. PCI modems do not have Ethernet jacks.

Step 2

Note the location of the modem. If the modem is inside the computer, it is either a PCI modem or another type of internal peripheral modem. However, some 56K modems use external connections, but they are not considered PCI modems because they do not use the PCI connection type. DSL and cable modems only come in external models, so if the modem is outside of the computer, it would be a DSL or cable modem. DSL and cable modems are primarily external because broadband connections are often shared by multiple computers. Because they are external, there is no need for a "master" computer that requires the modem on at all times to share the connection. The 56K PCI modems do not have enough bandwidth to handle more than one computer at a time, so the connection is not shared often.

Step 3

Examine how the modem connects to the computer if it connects to the computer at all. A cable or DSL modem may connect to a router to split its connection to multiple computers. Additionally, some cable and DSL modems may be able to connect to multiple computers. When this occurs, the cable/DSL modem is two devices in one or a modem/router combination. If the modem is internally connected to the computer, it would use a color-coded slot. If the modem is connected to a 4-inch white slot, it would be a PCI modem. If the slot is brown or black, it would be an ISA modem and if it is a 1-inch white slot, it would be a PCI Express modem.

Step 4

Test the modem's connection speed with an online speed test. The PCI modem tests around 56 kilobits per second for download and upload speeds, whereas the cable and DSL connections are likely to test between 5,000 and 20,000 kbps for download speed and between 96 and 5,000 kbps for upload speed. The cable and DSL modems should test at exponentially faster speeds.