In the context of Ethernet cables, “MHz” refers to megahertz, a unit of frequency that measures the bandwidth capacity of the cable.
The picture below shows a cable rated for 650 MHz.
Bandwidth, in this sense, is a range of frequencies within which the cable can reliably transmit data. This is shown in the picture below.
The higher the MHz rating of an Ethernet cable, the greater the frequency range it can handle, which typically translates to higher data transfer speeds and potentially better performance over longer distances.
???? In any communication system, the data rate scales with bandwidth
Ethernet cables are categorized based on their performance specifications, including maximum transmission speed, bandwidth (expressed in MHz), and the cable’s ability to mitigate crosstalk (interference between adjacent wires within the cable).
For example:
- Cat 5e (Category 5 enhanced) cables are designed to support frequencies up to 100 MHz and are suitable for network speeds up to 1 Gbps (Gigabit Ethernet).
- Cat 6 cables can handle bandwidths up to 250 MHz and are capable of 10 Gbps speeds over shorter distances (up to 55 meters, or approximately 180 feet), but they are more commonly used for networks running at 1 Gbps.
Cat 5 or Cat 6 are commonly used for home internet connections as they can sustain speeds up to 1000 Mbps
- Cat 6a (Category 6 augmented) cables support frequencies up to 500 MHz and can maintain 10 Gbps speeds over longer distances (up to 100 meters or approximately 328 feet).
- Cat 7 and Cat 8 cables offer even higher bandwidth capacities, with Cat 7 supporting up to 600 MHz and Cat 8 up to 2000 MHz (or 2 GHz), enabling 10 Gbps to 40 Gbps speeds, respectively, over 100 meters (328 feet) with improved shielding to reduce interference.
The MHz rating of an Ethernet cable affects not only the data transfer speed but also the quality of the connection over distance and its ability to support high-bandwidth applications such as video streaming, online gaming, and data centers.