# Cat5e vs Cat6



## StaticInMyHead

I've been searching the internet trying to find whether or not I will benefit from switching to Cat6. Any answers I find seem to be mixed; some people say today's applicatons see no benefit from Cat6 and some say gigabit is hindered by Cat5e. I'm going to be moving into a house and wiring it up extensively for gigabit networking. Would I be better off buying new Cat6 or sticking with Cat5e? I ran the network benchmark on Sandra and it reported that my gigabit bandwidth is 66MB/s minimum, and 72MB/s maximum. I've read that gigabit is supposed to operate at 125MB/s. Is the Cat5e slowing me down?


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## Comtrad

Currently there is a great deal of confusion among Ethernet cable buyers concerning whether to purchase Cat5E, or to use CAT6. Most of this confusion comes from a misunderstanding by the buyer that buying CAT6 cable will give them an "all gigabit" network. This is not the case. Unless every single component in the network is gigabit rated, then you will never have a gigabit network, because your network will always run at the speed of your slowest device. 

Cat5E cable of good quality can run near or at gigabit speeds, it just cannot be "certified" for this use. By comparison, CAT6 is designed especially for gigabit use, and is certified to operate at said speed. It becomes a matter of whether or not you want to pay all that extra money, for little or no noticeable improvement in the performance of you network. 

In most cases, it makes more sense to go with Cat5E. It is for this reason that most of your new installations in the private sector are going with Cat5E. It is more economical, performs well, and is readily available in many colors. 

Many IT professionals when asked about why they specified CAT6 for a specific job, often responded stated that they "wanted the best they could get." This is the line of thought behind many purchases of cable. 


Source


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## johnwill

Actually, CAT5e is fully specified for gigabit Ethernet. Unless you're running really long runs, you'll never see the difference.


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## StaticInMyHead

Like I said, with Cat5e, I get 66MB/s. I should be getting 125MB/s. Why is there a difference?


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## johnwill

I have no idea, but I really doubt it's the cable. I think you're also confusing the frequency of the carrier on the cable with the throughput. WHile the carrier is around 130mhz for gigabit Ethernet, the modulation is what allows you to transfer a gigabit of data on the link. Also, note that gigabit transfers use all eight wires, so if you have a flaw in the seldom used pairs, that could be an issue.

Finally, the make/model of the gigabit NIC has a lot to do with the rate you get, as well as how it's interfaced to the system. The standard 32 bit PCI bus will be saturated by a gigabit NIC, for instance.


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## StaticInMyHead

I wasn't confusing it with frequency; that's what Sandra's Network Benchmark results said. I get between 66MB/s and 72MB/s every time I run the benchmark. I searched what it should be and when I saw 125MB/s, I was concerned. It's no big deal, though. A single hard drive usually can't saturate a gigabit connection if it runs at 66MB/s.


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## Cellus

125MB/s is the standard's maximum on paper. Many factors, from length and attenuation, from cross-talk to return loss... you can use cable analyzers worth several thousand of dollars to test it all. You are most likely using a UTP CAT6 cable, which is affected by interference a lot more than a STP CAT6 cable.


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## crazijoe

StaticInMyHead said:


> A single hard drive usually can't saturate a gigabit connection if it runs at 66MB/s.


Maximum throughput of the PCI bus is generally 133MB/s. Also consider other peripherals that share that bus. (i.e. sound, USB, etc.) You really cannot take full advantage of Gbe unless you step up to a 64bit wide PCI bus.


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## Catalog

If you are starting at new premises with a new server and new network, should you go for Cat5e or invest in Cat6 ?


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## 2xg

Thanks for your feedback. This is a very Ancient Thread (year 2006) and time to Close now.


Catalog said:


> If you are starting at new premises with a new server and new network, should you go for Cat5e or invest in Cat6 ?


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