Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.

A Macbook Pro

macrumors 6502
Original poster
Aug 22, 2009
422
0
So I was in Officeworks today picking up some supplies while I ran across some Cat6 ethernet cables, I've heard about them and they were about $5 each so I grabbed two. Ran some speedtests and the results are pretty much the same, so I guess I'm future-proofed at least but what are the advantages of this new ethernet standard? I didn't do a ping test before hand but I did one after and I only had 1% jitter, not sure if that had anything to do with the cable or not, but yeah does anybody here run Cat6 or still on Cat5? I don't think I've ever bought an ethernet cable apart from these, I've just been using ones that came with modems/routers/Xbox, not sure if they're even Cat5 haha.
 
Most cables now are Cat 5e, which is certified for 100Mbps, but you can actually get gigabit speeds with it. Cat 6 is certified to be gigabit, so there often isn't a whole lot of benefit
 
Your internet connection is normally the bottleneck, not your internal cables. Cat 5e or 6, you probably won't notice a difference. If you are transferring files across our own network and not using the internet, you may notice a different.
 
Most cables now are Cat 5e, which is certified for 100Mbps, but you can actually get gigabit speeds with it. Cat 6 is certified to be gigabit, so there often isn't a whole lot of benefit

This is incorrect. Gigabit was spec'ed to run over plain old Cat5. See:
http://en.wikipedia.org/wiki/1000BASE-T#1000BASE-T

1000BASE-T Spec said:
Each 1000BASE-T network segment can be a maximum length of 100 meters (328 feet), and must use Category 5 cable or better. Category 5e cable or Category 6 cable may also be used.
 
It's highly unlikely you're going to get consistent gigabit speeds on CAT5. Since CAT6 has better crosstalk and inter-conductor insulation characteristics, you're much more likely to get higher speeds consistently. Of course, that's assuming you've put the right connectors, have the right infrastructure, etc.
 
I have a cat5 cable running more than 50' with an Airport Extreme basestation at each end. With iperf I'm running 940mbps across the link. 1000Base-T was built around cat5 cable, its specifically called out in the specification. Cat5 will work fine for gig.
 
CAT5 works quite often when using short distances (under 10 meters). Beyond that you will most likely run into problems. This cable is not officially recommended/certified for gigabit use. Cat5e is the enhanced version which is certified/recommended for gigabit use. Cat 6 too but this can even do 10 Gbit (up to a certain distance).

A good website (better than wikipedia which has a small error regarding cat5 and gigabit) would be the following: http://donutey.com/ethernet.php
 
CAT5 works quite often when using short distances (under 10 meters). Beyond that you will most likely run into problems. This cable is not officially recommended/certified for gigabit use. Cat5e is the enhanced version which is certified/recommended for gigabit use. Cat 6 too but this can even do 10 Gbit (up to a certain distance).

A good website (better than wikipedia which has a small error regarding cat5 and gigabit) would be the following: http://donutey.com/ethernet.php

While normally I would agree that Wikipedia is not to be regarded as a reliable source of information. However, in this respect, I fail to see where it is incorrect. The 802.3 specification itself calls out category 5 cable. It doesn't make mention of cat5e or cat6.

From section 40.1, page 151, of 802.3-2008 Section3:
"The 1000BASE-T PHY employs full duplex baseband transmission over four pairs of Category 5 balanced cabling. The aggregate data rate of 1000 Mb/s is achieved by transmission at a data rate of 250 Mb/s over each wire pair, as shown in Figure 40–2."

Section 40.7 goes on to say:
"1000BASE-T is designed to operate over a 4-pair Category 5/Class D balanced cabling system."

And then, section 40.7.2. says:
"The transmission parameters contained in this subclause are specified to ensure that a Class D link segment of up to at least 100 m will provide a reliable medium."

Maybe I'm missing it, but I don't see anything in here that says Cat5 won't work at lengths up to 100m, unless you're posulating that the 1000Base-T specification itself is incorrect?
 
It says cat 5 class d aka cat5d and not cat5. And then there's the fact that literally nobody recommends it because they all run into problems when using cat5 at long distances. They all use cat5e or 6 because that works without those problems.

And yes, standards can be "wrong". USB is one of the best examples. The standard says you have a speed of 480 Mbit/s, yet fw400 with only 400Mbit/s is mostly twice as fast. They are the most optimal speed you can get in the best of best situations. They theoretical speeds, not the ones you get in reality. The same goes for the much debated OOXML standard (which nobody uses because it is impossible to implement). Length of ethernet cables is also one of the things that should be read as "up to", it's again a theoretical distance, not what you'll get in reality.
 
Category 5d? Never heard of that. Got a link to share that outlines the differences between classic Category 5 and 5d?

At the end of the day, the point is moot either way. I doubt many vendors, online or otherwise, sell classic cat5 cable anymore. The fact of the matter remains, the gigabit specification calls out category5, not category5e or category6. Gigabit works on category5, I've got several runs in the house running with gigabit links and each tests over 900+ mbps with an iperf test.
 
Search with Google, you'll stumble upon some cat5d stuff and use the standard that you're using for your quote. Nowadays cat5e has superseded cat5 but some people still have old cat5 cables at home. As long as you use it for short distances, like you're seem to be doing, this should work. Long distances not so, you'll need cat5e or 6 or 7 for that. If you run into any strange problems exchange the cat5 cable for cat5e/6/7.
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.