The Need for Speed

For anyone working on a computer, a slow computer can be a great source of aggravation, especially when deadlines loom near. Many times, the computer is blamed for being too old. However, another cause could be the reason for the turtle speed: the data cable used to communicate with the computer. The rating of the low voltage cable installed to workstations has an impact on the speed of data that can be sent to and received from the network server or internet router. 

Can You Hear Me Now?

To really understand the differences in cable rating, it’s important to first understand that data is delivered to workstations in data packets.  After the data packet is sent, it is followed by a check sum value sent from the source computer to the receiving workstation.  If the data packet check sum value is not correct, the data packet is re-sent over and over again until the receiving workstation finally gets the correct message.  To humanize and make it easier to visualize,  the check sum process would go something like this: Two people are trying to talk across a room. The first person says something like, “Bring me a piece of cake” and then follows with, “Did you understand me?” If the second person says “No”, then the first person repeats the sentence, “Bring me a piece of cake.” until the second person finally says, “I Understand.” and delivers the piece of cake.

Because of this check sum process, the low voltage network may seem to work just fine. In actuality, slower network communication speed is occurring because the data packet has been resent numerous times before the receiving workstation finally receives it.

Invest Dollars Now to Maximize the Longevity of Network Communication Speed

Once the walls go up, data cable isn’t easily accessible and the cost to switch out cable every few years doesn’t fit any company’s budget. By investing the necessary dollars for the best cable before the walls go up, maximum communication speed is maintained for a longer period of time. 

Which Low-Voltage Cable Should You Invest In? 

The table below shows the cable rating and speed of each cable* currently available: 

*The TIA/EIA -568A defines structured cabling system standards for commercial buildings, and between buildings in campus environments and was developed through the efforts of more than 60 contributing organizations including manufacturers, end-users, and consultants. 

Although Cat 5e and Cat 6 cable have the same data bandwidth speed, we recommend Cat 6 or Cat 6a because of the ability to operate at a higher frequency which means that less noise or Near End Cross Talk (NEXT) exists to interrupt the data packet check sum at the receiving work station. Even with older computers connected to the network, faster communication will occur because of less data errors in the check sum process. However, to truly take advantage of the higher transmission frequency, both the sending computer and the receiving workstation must have the same higher frequency network cards.  Sometimes, older network cards or network switches will not operate at 250 Mhz, resulting in slower communication speed.

Simply put: a higher rated cable -  Cat 6a will provide better data transmission results. 

If you’re still not sure  which data cable is right for your project, give us a call at 440.953.8760 and we’ll help you figure it out.

Tim Pool, PE, RCDD Tec's Director of Electrical Engineering

Authored by Tim Pool, PE, RCDD. Tim serves as Director of Electrical Engineering for Tec Inc. Engineering & Design and is responsible for the engineering of power distribution, lighting, and control systems. He is a subject matter expert in National Electrical Codes and National Fire Codes and is a State of Ohio Electrical Safety Inspector. Tim is also a Certified Trainer with the National Center for Construction Education and Research and can often be found in the classroom as an instructor with the Electrical League of Ohio.