Cat5e vs Cat6 vs Cat6a: Which Cable Do You Need?

Networking · June 2026 · 7 min read

Why Your Cable Choice Matters

The cable running through your walls and ceiling voids is the backbone of every CCTV and networking installation. Get it right and your system will perform reliably for 15–20 years. Get it wrong and you'll face intermittent dropouts, poor image quality, and expensive re-cabling down the line.

We see it regularly across Northern Ireland — businesses and homeowners who had a system installed on cheap or inappropriate cabling, only to find their 4K cameras stuttering, PoE devices dropping offline, or network speeds nowhere near what they should be. The cable itself is a relatively small part of the overall project cost, so it makes sense to choose wisely from the start.

The three cable types you'll encounter most often are Cat5e, Cat6 and Cat6a. Each has its place, and understanding the differences will help you make the right decision for your specific installation.

Cat5e: The Legacy Standard

Cat5e (Category 5 enhanced) has been the workhorse of networking for over two decades. It supports speeds up to 1 Gbps at distances up to 100 metres and handles basic PoE delivery without issue. For many years, Cat5e was the default choice for CCTV installations, and there are thousands of systems running perfectly well on it across Northern Ireland today.

However, Cat5e is now showing its age. It was designed for a time when 1080p cameras were considered high-end and network demands were far more modest. The cable has limited headroom for crosstalk rejection, meaning that in environments with electrical interference — near fluorescent lighting, power cables, or industrial machinery — performance can degrade noticeably.

When Cat5e Still Works

If you're running a small system with a handful of 1080p cameras and short cable runs under 50 metres, Cat5e will do the job. It's also perfectly adequate for basic data networking in small offices where gigabit speeds are sufficient. But for any new installation, we'd generally recommend stepping up to Cat6 — the cost difference is minimal and the performance improvement is significant.

Cat6: The Sweet Spot for Most Installations

Cat6 is where we recommend most clients start. It supports speeds up to 1 Gbps at the full 100-metre distance and can handle 10 Gbps over shorter runs up to 55 metres. More importantly for CCTV work, Cat6 has significantly better crosstalk performance than Cat5e, thanks to tighter twist rates and a central spline that separates the four pairs of conductors.

This improved crosstalk rejection translates directly into more reliable data transmission. For 4K CCTV systems, where each camera might be pushing 12–16 Mbps of data continuously, that reliability matters. A single dropped frame might not seem like much, but over hours of recording it can mean the difference between usable evidence and corrupted footage.

Cat6 and PoE Delivery

Power over Ethernet is now standard for IP cameras, and Cat6 handles it beautifully. The thicker 23 AWG conductors (compared to Cat5e's 24 AWG) mean lower resistance, which translates to less power loss over distance. For PoE+ devices drawing up to 30W — which includes most modern PTZ cameras and high-powered IR illuminators — Cat6 delivers power more efficiently, especially on longer runs.

We've tested this extensively in our installations. On a 90-metre run, a Cat6 cable will deliver approximately 2–3W more power to the device than Cat5e. That might sound trivial, but for a camera operating at the edge of its PoE budget, those extra watts can be the difference between reliable operation and random reboots on cold winter mornings when power draw increases.

Cost Difference

A 305-metre box of quality Cat6 cable typically costs £15–£30 more than the equivalent Cat5e. On a typical 8-camera installation using 400–500 metres of cable, that's an extra £20–£50 on the total project cost. Given that the cable will be in place for a decade or more, this is one of the easiest decisions in any installation.

Cat6a: Future-Proofing for Demanding Environments

Cat6a (Category 6 augmented) is the premium choice. It supports 10 Gbps at the full 100-metre distance and offers superior shielding against electromagnetic interference. The cable is physically larger and heavier than Cat6, with an overall foil shield (F/UTP) or individual pair shielding (S/FTP) depending on the variant.

For most residential CCTV installations, Cat6a is overkill. But there are specific scenarios where it earns its place. Large commercial sites, industrial environments with heavy electrical interference, and installations where you want to guarantee 10 Gbps capability for future network upgrades all benefit from Cat6a.

Where Cat6a Makes Sense

We regularly specify Cat6a for factory floors, manufacturing facilities, and large warehouse installations across Northern Ireland. These environments often have variable-speed drives, welding equipment, and heavy three-phase machinery that generates significant electromagnetic interference. Cat6a's shielding keeps data transmission clean where Cat6 might struggle.

Multi-building campus installations are another strong use case. If you're connecting buildings across a business park or farm complex and need reliable 10 Gbps links, Cat6a delivers. For these longer backbone runs, the investment in Cat6a pays for itself by avoiding the need for fibre optic infrastructure on shorter inter-building links.

The Downsides

Cat6a cable is roughly 40–50% more expensive than Cat6 and significantly bulkier. The larger bend radius means it's harder to route through tight spaces, existing conduit, and older buildings with limited cable pathways. Installation takes longer because the shielded connectors require more careful termination, and every connection point needs to maintain the shield continuity to be effective.

How Cabling Affects CCTV Image Quality

This is a question we get asked frequently, and the answer is more nuanced than most people expect. The cable itself doesn't directly affect image quality — a 4K camera will still capture 4K images regardless of the cable. What poor cabling affects is the reliable delivery of that data to your recorder.

When a cable can't handle the data throughput — due to interference, poor termination, or exceeding its rated distance — the system compensates by dropping frames, increasing compression, or in severe cases, losing the camera feed entirely. The result is footage that looks fine most of the time but has gaps, artefacts, or frozen frames at the worst possible moments.

We've attended numerous call-outs across Belfast and Lisburn where the client's cameras were "playing up" intermittently. In many cases, the root cause was substandard cabling — either the wrong category for the application, poor-quality cable with copper-clad aluminium conductors instead of solid copper, or amateur terminations with excessive untwisting at the connectors.

Quick Comparison Table

Our Recommendation

For the vast majority of CCTV and networking installations across Northern Ireland, Cat6 is the right choice. It offers excellent performance, handles current and near-future demands comfortably, and the cost premium over Cat5e is negligible. We use Cat6 as our standard cable on every installation unless there's a specific reason to go higher.

For industrial sites, large commercial premises, or clients who want absolute future-proofing, Cat6a is worth the investment. And if you're planning a larger installation with runs exceeding 100 metres, you'll want to look at combining copper cabling with structured cabling principles and potentially PoE networking to get the best results.

Whatever cable you choose, make sure it's solid copper (not copper-clad aluminium), from a reputable manufacturer, and installed by someone who knows how to terminate it properly. The best cable in the world won't perform if the terminations are poor.