The simple differences between Cat5e, Cat6, Cat6e, Cat6a, Cat7, and Cat8 Cables.

• The Cat5 Family: Cat5, Cat5e

Cat5 is the oldest family that we’ll discuss, and it includes two standards, confusingly enough called Cat5 and Cat5e. Cat5 allows for speeds of 10 Mbit/s and 100 Mbit/s over distances of up to 100 meters.

That wasn’t quite sufficient even in 1995, so the original specification was quickly supplemented with additional requirements related to cross-talk mitigation, in the form of Cat5e, which can operate at 1000 Mbit/s (i.e. 1 Gbit/s) speeds.

But even in its improved form, the physical characteristics that this standard prescribed eventually became insufficient for high-speed applications.

Cat5 cables are rarely deployed anymore, but you can still find them in some existing installations.

• The Cat6 Family: Cat6, Cat6e and Cat6a

Cat6 was standardised in 2002 and further extends the performance requirements of the Cat5 family to allow for speeds of up to 1 Gbit/s over 100 metres and 10 Gbit/s over 55 metres.

• The Cat 6e Anomaly 

Cat 6e was introduced in the mid-2000s with a potential bandwidth up to 500 or 550MHz, improved shielding compared to standard Cat 6, and possible support for 10 Gbps over shorter distances.

Interestingly, “Cat 6e” was never an official standard. It has not been implemented or qualified by the TIA or any other reputable organisation or commission. It emerged as a marketing term used by manufacturers to describe cables that slightly exceeded standard Cat 6 specifications. This unofficial category has created confusion in the market, with no consistent definition or performance guarantee.

Caution: The term “6e” can be misleading, as performance varies significantly between manufacturers.

In 2018, another member was added to the Cat6 family – Cat6a. Cat6a has even tighter physical construction requirements, which allow cables to support speeds of 10 Gbit/s over 100-metre runs, too.

Originally, the tighter requirements related to materials and physical construction parameters made Cat6 cables more expensive than Cat5. This is no longer a factor, and Cat5 should certainly not be considered for new deployments.

Cat6 and Cat6a are currently the most widely deployed standards. Although they are being displaced by Cat7 and Cat8 for some applications, existing Cat6 installations don’t usually need complete overhauls.

• The Cat7 family: Cat7, Cat7a

Cat7 was originally developed more or less along with Cat6 for a maximum speed of 10 Gbit/s over up to 100 metres. The difference between Cat6 and Cat7 lies primarily in Cat7’s higher bandwidth (600 Mhz, versus Cat6’s 250 Mhz and Cat6a’s 500 MHz) and improved shielding.

The history behind how it happened is complicated and ridden with standardisation politics, but suffice to say that Cat7 never caught on that well – most people just settled for Cat6 and, later, Cat6e. Adoption was not helped by some early complications related to cable connectors, either.

Because it achieved those speeds through better shielding, Cat7 nonetheless found a good niche in industrial applications, as it did have better noise immunity than Cat6 cables. The thicker shielding made the cables less flexible, though, and harder to install in office settings.

That made Cat7 cables a relatively rare sight in London campuses.

ISO introduced a Cat7A standard later. This new standard was meant to future-proof Cat7 for the upcoming 40 Gbit/s Ethernet standard.

We’ll spare you the politics once more and just say that, while it also found a niche in AV applications, Cat7a wasn’t widely adopted by networking equipment manufacturers. This often makes the gains of Cat7a cables rather unreliable and has rendered Cat7 installations in general quite uncommon.

• Cat8 and its Two Classes

Cat8 cables technically come in two flavours, unimaginatively called Class I and Class II, which are often referred to as Cat8.1 and Cat8.2, respectively. Both cables have the same data transmission characteristics, though. What differs is how they achieve them, and what they are backwards-compatible with.

Cat8 cables allow for speeds of up to 40 Gbit/s over distances of up to 30 metres. 30 metres may not seem like a lot but it is enough for data centre installations, which is what Cat8 was primarily developed for. That being said, Cat8 is sometimes deployed outside the data centre, particularly for bandwidth-heavy applications.

Overview: Cat cable comparisons

There’s a clear trend behind our history lesson: network cables generally tried to extend the speed and range of operation.

Cat8 is somewhat exceptional, in that it was developed from the very beginning for specialised, data centre operations. This is why it targeted the kind of distances you see in data centres from the very beginning.

However, Cat8 has seen some adoption outside data centres as well, especially in bandwidth-demanding settings like AV editing or CAD.

Cabling Choice Dilemmas for Specific Applications

Knowing the main differences among Cat cables is not enough to ensure that you will install the right type in the right setting. You may be prone to go with the “latest” version just to make sure it’s the best.

But that can be needlessly expensive and quite overkill.

Let’s do something better with your time and your money and look at the ideal cable type for each application.

General Office Use: Cat6 vs. Cat7

If we look at the round-up table, we see that Cat7 has about the same technical parameters as Cat6a and can carry high-speed data slightly further than Cat6. We also said that Cat7 cables have higher signal bandwidth and are more immune to interference. So this should be straightforward – Cat7 is better, right?

Remember when we said Cat7 had a complicated history though? Well, here’s part of it.

Cat7 cables were initially developed for use with GG45 or TERA connectors. These are not quite like the 8P8C connectors you see on typical office equipment (which we usually call RJ-45, although that’s not quite right).

Cat7 cables with GG45 or TERA connectors are not fully backward-compatible with this equipment.

That being said, Cat7 cables do carry the same Ethernet signals, over the same set of wires – other than the physical characteristics, there’s no difference between Cat6 and Cat7 cables. There’s nothing preventing cable manufacturers from selling Cat7 cables with 8P8C connectors, which are backward-compatible, and allow you to benefit from the improved shielding characteristics of Cat7 cables to some degree.

So cable manufacturers did just that, with the caveat that 8P8C connectors have worse electrical contact properties than GG45 and TERA, so the performance guarantees of the Cat7 standards cannot apply.

The higher noise immunity of Cat7 cables can offer improved performance and reliability and may be worth the extra installation hassle, especially if physical space in cable enclosures is not at a premium and if EM interference is a major concern.

If you plan to use Cat7 with Cat6 equipment, then unless you have good reasons to suspect Cat7 cables would offer improved performance, there’s no reason to pay the extra fee. And if your network currently uses Cat6e cables and you are satisfied with them, upgrading is unlikely to offer significant benefits.

On the other hand, if you ever plan to upgrade your equipment to use Cat7-specific terminators, or if you just want to keep your options open, then installing Cat7 cables may be a good future-proofing option. The price difference is generally not too steep, and upgrades can be done incrementally, so the risk of over-committing resources is very small.

General Office Use: Cat5e vs. Cat6

If the previous question was a little unclear, this one is easy: you want Cat6 cables, specifically, Cat6a.

We are going to be celebrating Cat5’s thirtieth anniversary any day now. Cat5e vs Cat6 is not a question that you should even be entertaining anymore.

If you are deploying a new network, you should not be considering Cat5. If you are upgrading an existing network, this can be an excellent time to get rid of any Cat5 or Cat5e cables you might still have lying around.

Data Centre Use: Cat7 vs. Cat8

Given Cat7’s tortuous history and the fact that it never got an official blessing for the 25 Gbit/s and 40 Gbit/s standards, Cat8 is usually the better choice.

It’s faster and it’s future-proof – it’s the TIA/EIA official choice for these operating modes and was specifically designed for data centre use. Cat8 Class II cables are backwards-compatible with Cat7a equipment using GG45 or TERA connectors. So if you are also operating Cat7 equipment, you are not losing compatibility, either.

Specialised Applications: Cat7 vs. Cat8

Besides the Cat7-with-8P8C/RJ-45 use case we mentioned above, Cat7 did find some special niches, where it really sees enthusiastic and productive use, such as specialized audio-video (AV) applications.

More often than not, the choice, in this case, will be dictated by the specific equipment that needs to be installed. Cat8 Class II cables are interoperable with Cat7a equipment, though, so if you are already operating Cat8 equipment, it may be easier to go with Cat8 cables everywhere.

No matter which one you choose, though, it’s important to ensure termination continuity, especially in structured cable installations. If a Cat7 network segment is connected to the rest of your network through Cat6a patch cables, the Cat6a cables will be a bottleneck.

How Does the Durability of Cat6 Cable Compare to Cat7 Cable?

When it comes to choosing between Cat6 and Cat7 cables, understanding their durability is crucial for long-term network reliability. Cat6 cables are designed to last approximately a decade under typical conditions. In contrast, Cat7 cables boast an extended lifespan, often lasting up to 15 years.

Here’s a quick comparison:

• Cat6 Cable: Generally lasts around 10 years.
• Cat7 Cable: Typically offers a longer service life, around 15 years.

The enhanced durability of Cat7 cables makes them an appealing choice for installations where longevity is a key consideration.

What to Consider when Choosing Cabling Standards

Choosing the right cabling standard for an application isn’t always as clear-cut as we’d like. Cables don’t live in a vacuum – they’re deployed by companies with long-term plans, realistic budgets, and oftentimes inside existing networks.

So there are many factors that you can and should take into account, in order to make the correct cabling standard choice.

Choosing Cables According to Performance and Installation Area

Performance is the fundamental factor to consider when choosing a cabling standard or choosing among the Differences between cables.

Your network is only as fast as the cables and terminators allow it to be: a 40 Gbit/s port on a high-end network switch will not give you a 40 Gbit/s connection over a 100-metre Cat6 cable.

However, it’s worth remembering that cable performance is a limiting, not an enabling factor. Given adequate cables, a network will not run faster than its equipment allows. If all your computers and office equipment support speeds of up to 1 Gbit/s, plugging Cat8 cables into them will not make them faster.

The rule of thumb is that the performance parameters you choose for your company’s network should be sufficient for a period slightly longer than your most optimistic long-term plans. That makes your network future-proof and ensures it’s never a bottleneck in the execution of your business goals while avoiding over-investment early on.

There are other installation constraints that are worth taking into account besides cable distance. For example, you must be able to enforce the correct maximum bend radius for each cable type, and even well-shielded cables may not be able to reliably carry data if they’re in the proximity of a strong enough source of interference.

Price and Availability

As a general rule, as you go from Cat5 to Cat8, the price increases, but not quite by the same amount.

The progress in manufacturing technology has rendered the difference between Cat6 and Cat6a cables minimal. And thankfully the days when manufacturers would sell Cat6 cables as Cat6a cables for a higher price are over.

Similarly, Cat6a cables are so cheap that choosing Cat5 over Cat6 makes little sense, even if you do get a better quote for Cat5 cables.

Cat7 and Cat8 cables are more expensive. Given their unique performance characteristics for data centre use, the price difference for Cat8 cables is usually justified. For Cat7, it’s usually worth considering whether you get any substantial gains over Cat6e cables, especially given the complicated compatibility story and the limited availability.

Future Developments in Data Cabling Standards

While it may be too soon to say if Cat8 is here forever, or if Cat7 still has any future, there are things that we can be sure about. For instance, Cat5 is obsolete and unlikely to be used for anything other than legacy equipment.

Office and consumer equipment that supports Cat6a operation will be available for the foreseeable future. These are some useful data points to consider, and you often hear recommendations formulated in this manner, but it’s not quite the full story.

Earlier on, we talked a bit about how the industry progressed from Cat5 to Cat8.  That can give the impression that there’s a sort of a “cable industry” of its own, with its trends and cycles, and the rest of the world revolves around it.

The fact that you often hear of this or that office estate company in London using mostly Cat6e or Cat8 for some specific application can make that even more plausible – these cables are, almost literally, set in concrete.

There’s a grain of truth there but it’s not quite like that. There is a cabling industry, but it acts as an enabler and as the backbone, of the networking and Internet industry. The wider technological landscape is what drives the cabling industry.

That is worth considering, at least as much as general cabling trends. For example, even if you are not using any Cat8-capable equipment today, if you have any realistic goals of migrating to a private cloud infrastructure, or if you see more and more of your critical business applications migrating to the data centre, you may be using it tomorrow.

At the other end of the spectrum, if your business operations are mostly office-focused and will generally scale horizontally, the venerable Cat6a cables you have today may well be sufficient in five years, too.