Introduction
Ethernet cabling standards have evolved over the years to support faster data transfer speeds and improved performance. The original Ethernet standard released in the 1980s supported 10 Mbps over coaxial cables. This was followed by standards like Cat5, Cat5e and Cat6 supporting 100 Mbps to 1 Gbps speeds over twisted pair copper cabling (Ethernet LANs Chapter Figure 4-1: A Short History of …). The latest standard is Cat8, released in 2016, which supports speeds up to 40 Gbps.
Cat8 cabling is designed for transmitting high speed data of up to 40 Gbps for applications like data centers and server rooms. It consists of four twisted copper wire pairs just like previous standards. The key difference is that Cat8 cables have better shielding and are tested for higher frequency of up to 2 GHz. They also use new connectors called GG45 or TERA connectors for reliable connections.
What is Cat 8 Ethernet?
Cat 8 Ethernet cable is the latest iteration of Ethernet cabling that is designed to support speeds up to 40 Gigabit per second (Gbps) and frequencies of up to 2,000 MHz. It improves upon previous cable standards like Cat5, Cat5e, Cat6 and Cat7 by using more stringent specifications for things like crosstalk prevention, cable diameter and shielding.
Some key features of Cat 8 Ethernet cable include:
- Speeds up to 40Gbps
- Frequencies up to 2GHz
- Thicker gauge wire (23 AWG instead of 24 or 26 AWG)
- Additional shielding and protection from electromagnetic interference (EMI)
- Sturdier, more complex connectors to maintain shielding
Compared to Cat6 and even Cat7 cables, Cat8 is capable of much higher bandwidth while maintaining signal integrity over longer distances. The shielding and thicker cables make Cat8 more resistant to outside interference. All of this allows Cat8 to support emerging high-speed network technologies like 25GBASE-T and 40GBASE-T.
Advantages of Cat 8
Cat 8 Ethernet cable provides several advantages over earlier Cat 5, Cat 6 and even Cat 7 cables. Some of the main benefits of Cat 8 cable include:
Supports Up to 40 Gbps Speeds
One of the biggest advantages of Cat 8 cable is the ability to support network speeds up to 40 Gbps. This is a major increase compared to Cat 6’s maximum speed of 10 Gbps or even Cat 7’s 25 Gbps speed. As network demands continue to grow rapidly, Cat 8 provides the capability to handle extremely fast 40 GbE connections.
Ideal for Future-Proofing Networks
While 40 GbE technology is still relatively new and expensive, Cat 8 cable provides the capability to handle these faster speeds now and well into the future. Installing Cat 8 cable helps future-proof networks so that the cabling infrastructure is ready when 40 GbE devices become more commonplace.
Better Noise Immunity
With its improved twisted pair construction and shielding, Cat 8 cable is designed to reduce alien crosstalk and electromagnetic interference compared to earlier cable standards. This results in better noise immunity which allows Cat 8 cable to maintain signal integrity at very high frequency rates.
Disadvantages of Cat 8
Some key disadvantages of Cat 8 ethernet cable include:
More expensive than lower category cables – Cat 8 cable is more expensive than lower category cables like Cat 6 and Cat 6a due to the stringent specifications and shielding requirements. The connectors are also more expensive.
Compatibility issues with older hardware – Since Cat 8 is the newest ethernet standard, it may have compatibility issues with older networking hardware that doesn’t support the standard. Most modern equipment will work with Cat 8, but very old equipment may not.
Overkill for most home/office needs – For most home and office networks, Cat 6 or Cat 6a provides more than enough bandwidth and performance. Upgrading to Cat 8 will provide little benefit in most situations outside of specialized high-speed networks. As this Reddit comment points out, Cat 8 is overkill for most use cases.
In summary, for specialized high-speed networks Cat 8 provides future-proofing and extremely fast 40Gbps connections. But for everyday home and office use it provides little benefit over lower cost Cat 6/6a options.
Use Cases for Cat 8
Cat 8 Ethernet cables are designed for high-speed data transfer applications that require reliable connectivity. Some of the main use cases for Cat 8 cables include:
Data centers – With their massive amounts of servers and networking equipment, data centers require cables that can support 25 Gbps and 40 Gbps speeds for storage area networks and high performance computing clusters. Cat 8’s shielding helps prevent electromagnetic interference in these dense environments. According to Amazon, “Data centers primarily” are where Cat 8 is used today.
High performance computing – Research institutions, universities, and organizations with supercomputers need extremely fast data transfer for complex modeling and computations. Cat 8 provides the bandwidth capacity and low latency needed for high performance computing applications.
Financial trading – High frequency stock trading relies on executing trades in microseconds. Cat 8 cables deliver the speed and reliability for real-time data mirroring and virtualization that financial trading requires.
Research labs – Cutting edge research in science, medicine, and technology involves transferring huge datasets quickly and reliably. Cat 8 cables meet the rigorous connectivity demands of research labs and experimental facilities.
In summary, Cat 8 Ethernet cables are ideal for environments that need fast, secure, and dependable data transfer at high speeds over short distances. Their advanced shielding and bandwidth capabilities make them well-suited for data centers, supercomputing, financial trading, and research labs.
Cat 8 vs Fiber Optic Cables
Fiber optic cables have some distinct advantages compared to copper cables like Cat 8 when it comes to high-speed data transmission:
- Higher bandwidth – Fiber can support bandwidths upwards of 100 Gbps over long distances. Cat 8 is limited to 40 Gbps up to 30 meters.
- Longer distances – Fiber cables can transmit data over distances of several kilometers without degradation. Cat 8 runs are limited to 30 meters.
- Immunity to EMI/RFI – Fiber optic cables are immune to electromagnetic interference that can affect copper cables.
- Thinner cables – Fiber optic cables tend to be thinner and lighter compared to copper cables.
However, fiber optic cabling also comes with some downsides:
- More expensive – Fiber optic cables, connectors and transceivers are more costly than copper.
- Difficult splicing – Fiber cables require specialized tools and training to splice and terminate fiber optic connectors.
- Fragility – Glass fiber cores are more fragile than copper and can break when bent too sharply.
In general, fiber optic cabling is recommended over Cat 8 in the following scenarios:
- When cable runs will exceed 30 meters.
- For networks requiring bandwidths over 40 Gbps.
- In environments with lots of EMI such as industrial facilities.
- For connecting buildings on a campus or over longer distances.
Cat 8 may still be preferable for shorter patch cable runs, smaller office networks not exceeding 40 Gbps, and budget-conscious installations.
Cat 8 Cable and Connector Specs
Cat 8 ethernet cables have more stringent requirements compared to previous Cat generations in terms of shielding and cable construction to achieve the high speeds. According to the IEEE 802.3bt standard, Cat 8 cables must contain individual shielding for each twisted pair as well as an overall braided shielding.
The cable itself can use either foiled twisted pair (FTP) or shielded twisted pair (STP) construction. FTP cables have a foil shield around each individual pair. STP cables have a braided shielding around each pair. Both constructions provide enhanced noise protection compared to unshielded twisted pair (UTP) found in Cat 5/6 cables. The overall braided shield provides additional shielding from external noise sources.
For connectors, Cat 8 cables cannot use the standard RJ45 due to its limitations. Instead, Cat 8 cables utilize the GG45 (Generic Cabling for Gigabit Ethernet) connector which is compatible with 8P8C RJ45 connectors but provides improved performance. Another connector option is TERA connectors which offer ruggedized and fully shielded performance.
According to this article, the ISO/IEC 11801-1 standard specifies the following for Cat 8 components:
- Frequency of up to 2,000 MHz
- 4 connector interface standards allowed: TERA, GG45, ARJ45, and MRJ21
Installing and Terminating Cat 8
Installing and terminating Cat 8 Ethernet cable comes with some unique challenges compared to lower category cables like Cat 5e and Cat 6. Since Cat 8 is designed for 40 Gbps data rates, both the cable and connectors must be installed properly to achieve those high speeds.
One of the main challenges with Cat 8 installation is the need for special RJ45 connectors that meet the Cat 8 specifications. Standard RJ45 connectors used for lower category cables are not adequate for the stringent requirements of Cat 8 cabling. Improper connectors can ruin a Cat 8 cable’s ability to transmit 40Gbps and render it essentially useless.
Installers also need to use specialized termination tools when putting RJ45 ends on Cat 8 cable. The cable requires very precise stripping and crimping that generic tools cannot achieve. Using subpar tools often leads to connection issues and reduced performance.
Testing Cat 8 cable runs is also critical once installation is complete. Because of the fast speeds, any minor cabling issues like poor terminations or kinks can cause problems. Certified Cat 8 testers are required to validate that cable runs meet all the necessary performance standards before going live.
Overall, the exacting requirements of achieving full 40Gbps speeds over copper cabling means Cat 8 is a much more demanding cable to work with. Having the right tools and methods is a must for proper installation and termination.
Sources:
https://www.netans.com/2022/08/19/tips-for-setting-up-ethernet-in-the-home/
https://www.avforums.com/threads/complicated-home-theatre-wiring-question-help.956434/
Cat 8 Cost Considerations
When comparing Cat 8 to other Ethernet cable types, it’s important to consider both material and installation costs. Cat 8 cables themselves tend to be more expensive than lower-rated cables like Cat 6 or Cat 7 due to the advanced shielding and quality required. Expect to pay around 30-50% more for a Cat 8 cable. For example, a Cat 6 cable may cost around $0.20 per foot, while a similar Cat 8 cable would be $0.30+ per foot (https://www.linkedin.com/pulse/cat-8-cost-effective-easy-migrations-david-kim?trk=public_profile_article_view).
The connectors and hardware for terminating Cat 8 are also more expensive than lower-rated connectors. RJ45 connectors must be shielded and the connectors are physically larger to accommodate the additional shielding. Expect to pay $1-3 for Cat 8 connectors vs $0.50-1 for Cat 6 connectors.
Installation and labor costs are also higher for Cat 8. It takes more expertise and care to properly install the shielded, thicker cables and specialized connectors. Many electricians charge 20-50% more per drop to install Cat 8 over Cat 6. Difficulties working with the thicker cable also mean more time is required (https://computertechnicians.com.au/cat-7-vs-cat-8-which-is-better-in-2023/).
When evaluating the total project cost, the extra material and labor expenses of Cat 8 must be weighed against the long-term performance and future-proofing benefits.
Conclusion
In summary, Cat 8 Ethernet cable provides higher bandwidth and better noise immunity compared to previous Ethernet cable categories, with speeds up to 40 Gbps over 100 meters. The key benefits of Cat 8 include higher transmission frequencies, shielding for each twisted pair, and stronger cable construction. However, these advantages also lead to increased costs, complexity, and cable size.
Due to the high price and specialized requirements, Cat 8 should only be used for dedicated high-speed connections up to 40 Gbps within data centers and between servers. It is overkill for typical home or office networking uses. Fiber optic cabling is another option for long distance or high bandwidth runs. In most cases, Cat 6a or even Cat 6 cable will be sufficient for 1Gbps or even 10Gbps connections at much lower cost than Cat 8. Carefully evaluate your speed and transmission distance requirements when deciding if Cat 8 is worthwhile for your specific networking needs.
