CAT-5 vs CAT-6 Cabling & Gigabit Speeds

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jbkt23
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PostPosted: Wed May 21, 2025 11:11    Post subject: CAT-5 vs CAT-6 Cabling & Gigabit Speeds Reply with quote
So this question is somewhat a curiosity of mine and not based on any clear understanding of cable capacity or the standards that define them.
It has been posited that CAT-5 cable is rated up to 100 Mb transmission rate and conversely that CAT-6 is rated for 1 Gb transmission rate.

So first question is are the ratings limitations or just testing standards for certification of the cable type?

If you have 1 Gb service does that mean you would need a CAT-6 cable between your wifi router and the ISP modem?

I only have CAT-5 cable between any hardwired device on my network yet on some downloads I see rates of 15 to 20 MB B=8bits which translates to 120 Mb to 160 Mb a second rates. I have not done any official speed test to see what my ISP is delivering.

Well that's a start.

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ho1Aetoo
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PostPosted: Wed May 21, 2025 12:14    Post subject: Reply with quote
Depends on the specification of the cable and there are different standards ISO/IEC or EIA/TIA

and then it depends on the length of the cable...

I had a 25 year old 50m long CAT 5 cable lying around that didn't manage Gbit but only 100Mbit.

CAT 5e is officially gigabit-capable

CAT 6A is for up to 10Gbit

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Per Yngve Berg
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PostPosted: Wed May 21, 2025 12:18    Post subject: Reply with quote
Cat 5e is rated for 1G
Alozaros
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PostPosted: Wed May 21, 2025 16:01    Post subject: Reply with quote
CAT 5 is old standard and delivers indeed only 10-100MBit - translates around 10-12.5 MB per second
where CAT 5e, 6, 7 ,8 are 1Gig and above certified... can check on google..
https://www.cablek.com/cat5-vs-cat5e-vs-cat6-vs-cat7-vs-cat8-what-are-their-differences

the most important is your router CPU as this is vital for WAN to LAN performance....
as well as the other announced ...type of cable and length plays role too...as well some cable loops and client compatibilities...play role too... Cool

for example your Tp link Archer has a single core CPU, that can handle around 200Mbit without acceleration, with acceleration may handle a bit more, but it is a questionable performance that depends on many factors...

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Last edited by Alozaros on Wed May 21, 2025 17:23; edited 1 time in total
ho1Aetoo
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PostPosted: Wed May 21, 2025 16:35    Post subject: Reply with quote
As already mentioned, this depends very much on the length.

CAT 6 supports 10Gbit but only with a length <55m

CAT 5 can also support 1Gbit depending on the cable quality and length

CAT 5e officially supports 1Gbit for lengths up to 100m
CAT 6A officially supports 10Gbit for lengths up to 100m

CAT 7 was not specified for RJ45, CAT 7 officially uses TERA connectors with larger distances required for ≥600Mhz and was developed for CCTV

https://en.wikipedia.org/wiki/TERA


CAT 8.x uses RJ45 connectors again and should allow bandwidths up to 40Gbit in the future

and as already mentioned, there are different standards

ISO/IEC and EIA/TIA
ISO/IEC = International Organization for Standardization/International Electrotechnical Commission
EIA/TIA = Electronic Industries Alliance/Telecommunications Industry Association (USA)

it is generally said that ISO/IEC is stricter

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Alozaros
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PostPosted: Wed May 21, 2025 17:38    Post subject: Reply with quote
I made my house with cat 7 (flat SFTP) but terminated with RJ45 as they can be rj45 as well, but yes in general they are certified TERA, as they came out...in fact all cables after CAT 6 are thicker, stiffer and not that flexible for a home wrapping, i was lucky to find CAT7 flat options as a touch better...not that i needed it...but at the time it was a good option... now optics are way better...and way faster..

https://stl.tech/blog/what-are-cat7-cables/#2_RJ45_Cat7_cable

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jbkt23
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PostPosted: Wed May 21, 2025 21:03    Post subject: Reply with quote
Thanks for the comprehensive replies. This will aid in any future trouble shooting if the need be.
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PostPosted: Wed May 21, 2025 21:45    Post subject: Reply with quote
ho1Aetoo wrote:
CAT 5 can also support 1Gbit depending on the cable quality and length
ho1Aetoo wrote:
I had a 25 year old 50m long CAT 5 cable lying around that didn't manage Gbit but only 100Mbit.

To clarify here, CAT 5 only does 1 Gbit/s link speed in patch cables AFAIK. I think the longest patch cable I remember linking at Gigabit was 15 feet, but I could be mistaken. It was about the time that I started implementing Gigabit Ethernet in my home network ~20-25 years ago.

Sorry, had to jump on the must be relevant bandwagon. Rolling Eyes Twisted Evil Laughing

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ho1Aetoo
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PostPosted: Thu May 22, 2025 8:10    Post subject: Reply with quote
@Alozaros

I know that such cables are available.
The question is whether they are actually certified CAT 7 plugs or CAT 6A plugs.

There are no CAT 7 connectors at all from the well-known manufacturers.

As the manufacturers preferred to continue using RJ45 for 10Gbit, CAT 6A was subsequently specified.

Quote:
However, in 2006, Category 6A was ratified for Ethernet to allow 10 Gbit/s while still using the conventional 8P8C connector. Care is required to avoid signal degradation by mixing cable and connectors not designed for that use, however similar. Most manufacturers of active equipment and network cards have chosen to support the 8P8C for their 10 gigabit Ethernet products on copper and not GG45, ARJ45, or TERA connectors as Class F would have originally called for.[4] Therefore, the Category 6 specification was revised to Category 6A to permit this use; products therefore require a Class EA channel (ie, Cat 6A).



I have CAT 7 4x2xAWG26/7 (7 x 0.160 mm) copper flex cable (no rigid copper core but stranded wire)

But they only have CAT 6A plugs for the reasons mentioned above

from your link

https://stl.tech/wp-content/uploads/2022/08/img9.jpg

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