# Strange Transfer Speeds Using CAT5



## LiveOrDie (Dec 21, 2012)

This is strange as i understand CAT5 is only 10/100 and normal transfer rates from 1 pc to another is normally around 10MB/s but for some reason i get CAT6 Speeds out of it my router it does support gigabit speeds but i just cant understand how some times i get 100+ MB/s + transfer rates and other times i get like 10MB/s + transfer rates ideas? 

My routers is a Netgear n600


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## natr0n (Dec 21, 2012)

It happens, routers aren't always consistent .


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## Disparia (Dec 21, 2012)

The router or computer might be flipping between 100Mb and 1Gb. Since your NIC and router are both gigabit devices, the negotiated speed is initially 1Gb, but after too many errors they renegotiate at 100Mb. My guess anyway. I'd look at the NIC status right after a start up. If it's 1Gb, start a file transfer and see if it downgrades.

- Buy some new cables. CAT6 isn't all that expensive anymore, or in a pinch, short runs of CAT5e will do 80MB/s+.

or

-  Manually set your NIC to 100Mb.


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## FordGT90Concept (Dec 21, 2012)

How long is the cable?  Does it run through any walls/close to power lines?


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## Frick (Dec 21, 2012)

Cat 5 is 100mb/s, but I'm pretty sure that's cat 5e you have there which is 1gbps.


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## Aquinus (Dec 21, 2012)

Live OR Die said:


> This is strange as i understand CAT5 is only 10/100 and normal transfer rates from 1 pc to another is normally around 10MB/s but for some reason i get CAT6 Speeds out of it my router does support gigabit speeds but just cant understand how some times i get 100+ MB/s and other times i get like 10MB/s ideas?
> 
> My routers is a Netgear n600



What are you using for NICs? I know if you're using something like a PCI gigabit ethernet card, you're not going to see really high speeds because you're going to saturate the bus or if the integrated NIC on one of your machines could be tied to the PCI bus.

Have you tried ruling out the router and plugging the two machines into eachother with the same cable? Modern NIC don't need a crossover cable and you could try to send data from one machine to another that way.

Finally, what kind of drive setup do you have in the other machine. Are you certain that it's not an I/O bottleneck, because >100MB/s is a lot of data in a short amount of time for a single hard drive if that is what the other rig has. You still need to read and write just as fast as the LAN connection to achieve those speeds.

I have a ruby script that sends garbage data over a socket to connections that come in and prints out the throughput of this said garbage data. You could try saturating your network with that to see what kind of number come out. It removes the I/O aspect of the problem. If you're interested I can try and find it. I've used it for testing bandwidth inside the network where I work.


Edit: I found it. Here you go if you want to give them a try. They're pretty basic, you'll need to edit the hostname/IP in the client.rb file to the machine that's running server.rb. It just loops, you need to kill the window or ctrl+c to stop both of them since they run in an infinite loop.

client.rb

```
#!/usr/bin/ruby

require 'socket'

s = TCPSocket.new '10.0.0.2', 4586

part_count = 0
average_bytes = 0
average_time = 0
cps = 0
    
print_freq = 1
    
loop do
  t1 = Time.new.to_f
  data = s.gets
  t2 = Time.new.to_f
  average_time = (average_time + (t2 - t1)) / 2
  cps = data.length / average_time
  part_count = part_count + 1
  average_bytes = (average_bytes + data.bytesize) / 2
  if part_count % print_freq == 0 then
    bspeed = average_bytes / average_time
    bspeed = "%.3f" % (bspeed / 1024 / 1024)
    p "Speed: #{bspeed} MB/s"
  end
end
```

server.rb

```
#!/usr/bin/ruby

require 'socket'

server = TCPServer.new 4586

o = [('a'..'z'),('A'..'Z')].map{|i| i.to_a}.flatten;

begin
  str_msg = (0..(50 * 1024 * 1024)).map{ o[rand(o.length)] }.join;
  client = server.accept
  loop do
    client.puts str_msg
  end
rescue Exception=>e
  p 'Lost connection.'
  exit
end
```

Example output on client side

```
~$ ruby1.9.3 client.rb 
"Speed: 112.601 MB/s"
"Speed: 108.845 MB/s"
"Speed: 109.384 MB/s"
"Speed: 110.130 MB/s"
"Speed: 108.468 MB/s"
"Speed: 115.494 MB/s"
"Speed: 113.947 MB/s"
"Speed: 114.085 MB/s"
"Speed: 106.919 MB/s"
"Speed: 114.459 MB/s"
"Speed: 106.645 MB/s"
"Speed: 114.418 MB/s"
"Speed: 106.698 MB/s"
"Speed: 116.128 MB/s"
"Speed: 115.969 MB/s"
"Speed: 116.154 MB/s"
"Speed: 116.023 MB/s"
"Speed: 116.184 MB/s"
"Speed: 116.414 MB/s"
"Speed: 105.733 MB/s"
"Speed: 112.684 MB/s"
"Speed: 114.037 MB/s"
"Speed: 105.961 MB/s"
"Speed: 112.643 MB/s"
^Cclient.rb:16:in `gets': Interrupt
	from client.rb:16:in `block in <main>'
	from client.rb:14:in `loop'
	from client.rb:14:in `<main>'
```

This is a result on HP Procurve, netgear unmanaged switch, and a linksys gigabit switch from a server to a tower with both using gigabit (and gigabit between the switches, client -> linksys -> netgear -> procurve -> server). If I used the Mac with a Thunderbolt ethernet adapter, it is closer to 130MB/s.

I didn't lie when I said it was basic, but it works, at least for me it did on both Ubuntu and a Mac. I don't see why it wouldn't work on Windows, just use ruby 1.9.x. I recommend using the same I did, which is 1.9.3.


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## newtekie1 (Dec 21, 2012)

Jizzler said:


> The router or computer might be flipping between 100Mb and 1Gb. Since your NIC and router are both gigabit devices, the negotiated speed is initially 1Gb, but after too many errors they renegotiate at 100Mb. My guess anyway. I'd look at the NIC status right after a start up. If it's 1Gb, start a file transfer and see if it downgrades.
> 
> - Buy some new cables. CAT6 isn't all that expensive anymore, or in a pinch, short runs of CAT5e will do 80MB/s+.
> 
> ...



Cat5e will do 1Gbps over the same lengths that Cat6 will do, CAT6 give not advantage of Cat5e in a Gigabit environment.  Cat6 only becomes necessary in 10Gbps environments.

And his router is actually only a 100Mbps device, not 1Gbps.

My guess is that it is just Windows screwing up the speed reading.  Likely it is just reporting a burst speed reading of 100MB/s when the actual overall speed is 10MB/s.


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## Disparia (Dec 21, 2012)

Looks gigabit to me. Plus, this particular model was one I was considering last month when I needed to buy a new one so I already knew it's specs.


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## newtekie1 (Dec 21, 2012)

Jizzler said:


> Looks gigabit to me. Plus, this particular model was one I was considering last month when I needed to buy a new one so I already knew it's specs.
> 
> http://img.techpowerup.org/121221/WNDR3700-features-diagram18-5829.png



My bad, I misread the original post as saying his router didn't have gigabit ports so I assumed he had this version of the N600:

http://www.netgear.com/home/products/wirelessrouters/high-performance/wndr3400.aspx#two


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## LiveOrDie (Dec 22, 2012)

Jizzler said:


> Looks gigabit to me. Plus, this particular model was one I was considering last month when I needed to buy a new one so I already knew it's specs.
> 
> http://img.techpowerup.org/121221/WNDR3700-features-diagram18-5829.png



Yep that's the one i have i did state in the OP that my router support gigabit speeds, Here's some more info the cables are only CAT5 they don't say CAT5e on them and I've got these speeds from my system to my Media PC and also my GF PC ether have a SSD just a hard drive, The longest cable would be 4m, My friend has a R6300 and doesn't get these speeds on CAT5 or CAT5e because i thought it was normal and we were using them for a LAN, And there the correct speeds windows isn't reporting wrongs as i send bluray rips of up to 10gb from my system to my media PC and they only take a few minutes at the most.


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## newtekie1 (Dec 22, 2012)

A short run of standard CAT5 can support 1Gbps, and 4m is a pretty short run, they aren't guaranteed to, but they can do it as long as the cable has 4 pairs or wires and not 2.  Though I've also seen CAT5e cables not labeled directly as CAT5e, honestly I haven't even seen CAT5 cable available for sale in years, so chances are they are CAT5e cables unless they are really old.(though Australia might have older stock?)

If you are really using CAT5 cable, then it is possible that it is giving 1Gbps speeds sometimes, but the adapters are dropping down to 100Mbps sometimes as well when the cable is causing too many errors.

When you are getting the 10MB/s speeds I'd check your adapter status again and see if it has dropped down to 100Mbps operation.


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## LiveOrDie (Dec 22, 2012)

They could be CAT5e but i don't think so they are old and on all 3 cables they say CAT5, also my friends router uses the same cables and we couldn't get it to do the speed that mine does using CAT5 or CAT5e using 2m cables, I just did a quick test and i was getting 10MB/s transferring a file across so i unplugged the cable plugged it into another port and bang around 100MB/s unplugged it plugged it back to the other port 10MB/s 

Port 4





Port 3


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## newtekie1 (Dec 22, 2012)

When you are getting the 10MB/s check your adapter status.  Chances are, since it sounds like you might actually be using CAT5 cable, that the connection is unstable.  Sometimes giving a 1Gbps link, and sometimes giving a 100Mbps link.  Each time you unplug and replug the cable the NIC in your computer and the Router re-negotiate the link speed.  So sometimes it is getting negotiated at 1Gbps and sometimes only 100Mbps.  That is what happens with CAT5 cable.  Sounds like you need to get some new cables, CAT5e can't be that expensive, I buy it for about $0.10 a foot...


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## Jetster (Dec 22, 2012)

Live OR Die said:


> This is strange as i understand CAT5 is only 10/100 and normal transfer rates from 1 pc to another is normally around 10MB/s




There is no speed diff between cat 5 and 6. At least at short distances. 

The reason your sometimes getting slower speeds is most likely a drive or the system is busy, maybe a connection, router.

What router?      Routers very widely in speed. Update the firmware may help

The reason I say a drive is I just got done testing a router wireless speeds and I couldn't figure out why all of a sudden my speeds were changing. Turns out my drive was going south. Switch drive and it was fixed. And that ws at 10MB/s not 100


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## LiveOrDie (Dec 22, 2012)

My routers is a DGND3700 and it also says 1.0Gbps on my NIC ill have to check on my other system to see as well ill be picking up some CAT6 soon, Jetster when you say there no speed difference my tests tell me other wise when i go over my friends before he got CAT6 cables he was using CAT5e and they never use to transfer faster than 10-20 MB/S.


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## Jetster (Dec 22, 2012)

He must of had a bad cable. Cat 5 will do over 100 MB/s 

http://www.cableorganizer.com/articles/cat5-cat5e-cat6.htm

But the speeds of routers and nic very wildly. Some claim Gigabyte but stick with quality parts. 

The Netgear DGND3700 is a quality router. Your wired speeds will be good. But the weekest link will slow you down.


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## LiveOrDie (Dec 22, 2012)

Jetster said:


> He must of had a bad cable. Cat 5 will do over 100 MB/s
> 
> http://www.cableorganizer.com/articles/cat5-cat5e-cat6.htm
> 
> ...



Same cables as i use at home  only difference is his router is a R6300 WiFi and cost more than mine


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## newtekie1 (Dec 22, 2012)

All my cabling is CAT5e and I easily sustain 110MBps transfers. CAT6 is only needed for 10Gbps.


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## Aquinus (Dec 23, 2012)

newtekie1 said:


> CAT6 is only needed for 10Gbps.



Or >50ft for 1Gbps. I'm pretty sure Cat 5e is rated for 50 ft. and CAT 6 is rated for 100 ft by spec iirc. Please correct me if I didn't remember correctly. It's something like that, CAT6 supports longer lengths at the same speed at 5e.


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## Frick (Dec 23, 2012)

Aquinus said:


> Or >50ft for 1Gbps. I'm pretty sure Cat 5e is rated for 50 ft. and CAT 6 is rated for 100 ft by spec iirc. Please correct me if I didn't remember correctly. It's something like that, CAT6 supports longer lengths at the same speed at 5e.



Nope, 100 meters for 5e. 50ft or so is for cat 5.


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## newtekie1 (Dec 23, 2012)

CAT5 is not rated for 1Gbps at any length, however it is generally accepted that it will work at short distances as long as the cable has 4 pairs(some CAT5 only had 2 pairs and won't support gigabit at all).

CAT5e and CAT6 are both rated and will handle 1Gbps at up to 100m(328ft).

CAT6 will handle 10Gbps at 37m(121ft) guaranteed, but can handle 10Gbps all the way up to 55m(180ft) in favorable crosstalk conditions.

CAT6a is rated to handle 10Gbps up to 100m(328ft).


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