Understanding Ethernet Cables: Exploring the Differences Between Cat3, Cat5, Cat5e, Cat6, Cat6a, Cat7, and Cat8

In the world of networking, Ethernet cables play a critical role in connecting devices and moving data reliably. With multiple categories available, ranging from Cat3 to Cat8, it can be difficult to determine which cable type is appropriate for a given environment.

Choosing the wrong category can limit performance or require costly upgrades later. For a broader understanding of how Ethernet cabling fits into overall network design, see our Comprehensive Guide to Network Cabling.

(Also, that comparison chart in your header image is good visual reinforcement. Shows speed, bandwidth, and shielding differences clearly. Keep that.)

Cat3

Cat3 cables were common in early networking environments.

• Supports speeds up to 10 Mbps
• Primarily used for voice and legacy data
• Mostly obsolete for modern networking

Today, Cat3 is typically only found in older telephone wiring and is not suitable for business networks.

Cat5

Cat5 improved on earlier standards and was widely adopted for early LAN deployments.

• Supports speeds up to 100 Mbps
• Common in older homes and offices
• Uses four twisted copper pairs

Cat5 is now largely outdated and replaced by higher-performance standards.

Cat5e (Enhanced)

Cat5e significantly improved performance over Cat5 and remains widely deployed.

• Supports speeds up to 1 Gbps
• Improved interference resistance
• Backward compatible with Cat5

Cat5e still works in many environments but may not meet future business demands.

Cat6

Cat6 offers higher performance and tighter installation specifications.

• Supports 1 Gbps at 100 meters
• Can support 10 Gbps at shorter distances (~55m)
• Common in modern business networks

Performance depends heavily on proper installation practices. Details like termination quality and twist preservation directly affect results, which we explain in Why the Twists in Cat6 Cable Matter More Than You Think.

Cat6A (Augmented)

Cat6A improves on Cat6 by supporting higher speeds over longer distances.

• Full 10 Gbps at 100 meters
• Better shielding against interference
• Thicker and more rigid cable

Cat6A is often chosen for new commercial builds or future-proof upgrades. We break down the practical differences in Cat6 vs Cat6A: Which Ethernet Cable Should Your Business Use?

Cat7

Cat7 cables provide increased shielding and higher frequency support.

• Supports speeds up to 10 Gbps
• Operates up to ~600 MHz
• Uses individually shielded twisted pairs (S/FTP)

Cat7 is less common in U.S. commercial installs due to connector compatibility and cost.

Cat8

Cat8 is designed for very high-performance environments.

• Supports 25–40 Gbps
• Limited to short runs (~30 meters)
• Typically used in data centers

Most business environments don’t require Cat8, but specialized applications may.

Choosing the Right Ethernet Cable

The right cable depends on more than speed ratings. Distance, interference, future growth, and installation quality all matter.

Many performance issues come from installation mistakes rather than cable category itself. We outline common pitfalls in Common Ethernet Cabling Mistakes That Hurt Network Performance.

For businesses, Ethernet cabling should be part of a structured infrastructure plan rather than a standalone decision. A properly designed system supports expansion and avoids costly rework, as explained in A Business Owner’s Guide to Structured Cabling (No Tech Jargon).

Planning a Professional Installation

If you’re planning network upgrades, new construction, or infrastructure improvements, visit our network cabling services page to learn how Cabling Wizards handles structured cabling design, installation, testing, and certification.