cat5e when to use 350Mhz or 500Mhz

When is it practical to use a 500Mhz cat5e cable?

When is it practical to use a 350Mhz cat5e cable?

Are all cat6 rated cables 500Mhz?

Is their that much difference in total bandwith that can be accomplished when running a 500Mhz cable over a 350Mhz cable? In otherwords if I was to run a 350Mhz cable on a 1000baseT backbone connection would I see any performance loss over a 500Mhz cable.
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dont' know if this helps. but take a look at the descriptions at:

It will not help on standard 1 gig but there is some 2 gig staff out there and more coming, i do not think it will be long till mose gig stuff can run 2 gig.

To get the full speed of 2 gig you need the 500MHZ  
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DMS-XAuthor Commented:
Hmmmm this is interesting I thought that their would be a clear answer on this one.


So basically 500Mhz is useless unless you are running a 2 gig (2000BaseT) connection.
I am not convinced. Why then has 500Mhz cat5e cable been available for such a long time, probably before 2 gig connections.
I have never seen 2000BaseT stuff but I will take your word on it.
Could it be with 500Mhz cable on a 1000BaseT line that you get a better quality signal because of the greater bandwidth. Meaning less packet errors or collisions?

I think technology learns to know infrastructure limitation and trying to improve data transfer rates based on the infrastructure we currently have; My case here based on the fact that when phone lines were able to hold up to 14Kbps, no one would imagine the transfer of a large quantity of data such as 750K, not to mention 2MB and up to 10MB of data through standart RJ11 copper wire. I think that in the near future we will see NICs that are able to use 10GB based on the current Cat5/Cat5e cables (and I know that this is the trend companies are developping)...

When is it practical to use a 500Mhz cat5e cable?

Presently, it is not practical.  However, with that said, I prefer to use CAT6 for my longer warehouse/cross building drops.  Since 350Mhz rated CAT%e is sufficient for gigabit based networking, 500Mhz is simply overkill.  But, if you plan to agressively adopt new network mediums, it might work out to be a good (albeit expensive) cable invenstment.

When is it practical to use a 350Mhz cat5e cable?

I would usggest always using cat5e rated cable, but especially when gigabit ethernet it a possibility/requirement.

Are all cat6 rated cables 500Mhz?

Not a sure bet. Do your homework if a CAT6 purchase in is your future.

Is their that much difference in total bandwith that can be accomplished when running a 500Mhz cable over a 350Mhz cable? In otherwords if I was to run a 350Mhz cable on a 1000baseT backbone connection would I see any performance loss over a 500Mhz cable.

There is more potential, however, using a higher category CAT cable will not magically induce your 100base NICs to function @ 1000Mbits.  Theoretically plain old CAT5 cable should support their if your looking for a safe bet, use CAT5e.  If you have gobs of money and plan to go nuts with your network, get CAT6.

There very little cost diffrence between 350 and 500 .

I have posted a few commnets in regards to cabling the past month, I have included some information that may help clarify some things. The answer below was in respect to someone trying to figure out which way to go, CAT6 or CAT5. Though the cable you may be looking to putchase is rated for 350 or 500Mhz, the industry standards do reconize those specifications of that paticular cable company as the defacto industry standard. Also if the connectors that the cables are connecting to are a standard CAT5E, then your 350/500 MHz was just downgraded to 100Mhz.

What is important about the frequency of the cable, is not how high, but how much headroom. Headroom is a ratio between noise and attenuation dB strength, once this falls below a certian level, the paticular frequecy is useless for data transmission.
Think of headroom as driving a car that is 7 feet wide down two differnt roads at a set speed of 100MPH, One road is 10 feet wide, the other is 15 feet wide. You only need 7 feet so both will work, but one offers a little more room for margin of error.

So what does this mean to you, not alot, the usable bandwidth is for equipment providers to develop new applications on a given cable. The more usable bandwidth, less limitations. If you a really concerned about performance, then I would recommend using fiber, the limitation of fiber is the equipment at each end, whereas copper is limited by the eqipmnet, the envirment and the cable itself.

CAT6 has a usable bandwidth (do not confuse with throughput) of 250Mhz. Where CAT5E has a usable bandwidth of 100Mhz. Now 10Base-T operates at 7.5 Mhz, 100Base-T @31.25Mhz and 1000Base-T@62.5Mhz, all within the CAT5E standard. The higher grade cable does not dictate it can be run a longer distance, actual based on cabling standards all cables (copper or fiber) used inthe horizontal runs cannot exceed 90M (295 feet), the other 10M is for cross connects and patch cords.  Refer to below paragraph taken from TIA:

" 100 Mbps will have the same constraints as 1000 Mbps or even worse due to the quality of the electronics. The 2 volt nominal signal for both drops away due to signal strength past 295 feet in the link, which then allows for a further 33 feet for patching and cross connecting. 10BaseT uses a 5-volt nominal signal that can support further distances more frequently, but it still comes down to the quality of the transceivers. For example, just because port 1 in a switch can support a 110% of the recommended length for a particular protocol doesn't mean that port 2 will. You can have great noise reduction, but if your signal strength isn't sufficient any extended length support is lost. The problem network administrator’s face is that they don't know which ports have the best signal strength to support longer than standard runs. Cycling back to 10BaseT half duplex is the safest bet for such circumstances, but then not only slows the speed, but introduces localized collisions and in many cases CRC/FCS errors. "

Also, CAT6 is the latest and greatest, yet not everyone is certified to install it. Also, since you are in a multi-floor building, the assumption is that the electrical system powering the building can become complicated. Based upon panel, transformers, feed cables; they might have a negative impact on your cabling system. This is usually particular in the closets where the network equipment, electrical wires and data cabling come into close proximity. If the cable is installed wrong, the cost of going CAT6 is wasted. Also the horizontal cables running from the patch panels to the desks have to be installed correctly, if you are using partitions, guess what, the internal cabling routes in a partition exceed the maximum bend radius of the CAT6 cable as per ANSI/TIA/EIA-568-B standards.

Also you have stated that you are using standard Ethernet switches, which means that they operate within the 10/100/1000 standards, which is well within the performance of CAT5E cable. The cost to go from CAT5E to CAT6 is about 30% (with a certified contractor). Go with CAT5E for your horizontal runs and use the 30% you are saving to upgrade your switches to include some type of fiber optic connection. Run a 12 strand fiber between each floor. Yes fiber is more expensive then most cabling, guess what, the light is not constrained by the fiber itself, but by the transmitting and receiving equipment. Copper wire is limited based upon its physical characteristics along with the equipment connecting to it. So if some really cool stuff comes out in three years, you just have to replace the switches (maybe even just a module) verses the entire cabling infrastructure.

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