Gigabit network only transferring at 10MB/sec speeds

I have a home network setup the following way.

Cable modem into cisco-linksys E4200. 2 of the ports going out from the router plug into the wall, where one goes to the master bedroom and one goes to the living room. Once it gets to the wall jack in each of those rooms it goes out to a gigabit switch. Each of those two rooms has a computer and a TV connected, and the living room as a blu-ray also connected to the switch.

The third port going out from the E4200 router goes to another gigabit switch, which is connected to a couple more computers in that room.

All of the cables are either cat5e or cat6. The long cables running through the wall from the server room to the living room and master bedroom is 24gauge 4pair cat5e, it was run by a general contractor.

Now for the problem.

When I transfer between any of the computers on the network as it sits I get 11MB/sec. I get that number by clicking more details on the file transfer. In the network tab of task manager it sits pretty consistently at 10%.

If I move any of the computers to be connected to the SAME switch (i tested all 3) i can transfer around 60MB/sec.

Based on this testing my initial instinct is to say that the cable running between the rooms is limiting the transfer speed. However the cable is cat5e and rated for gigabit. Neither of the runs are anywhere near 300ft long. Plus the consistency of the transfer speeds at 11MB/sec makes me think it's being clearly capped at 100base-T speeds as opposed to just slowing down due to interference of the cable.

As a side note there is a place in the router that tells you the speed of each port. For some reason it has one of my ports listed as gigabit and the others listed as 10/100Mbps. The yellow 3 foot cable i have is listing as gigabit, when i swap it with another cable in the router it changes the gigabit port to the one this yellow cable is on, very odd, however regardless of whether the router says its gigabit it only transfers at 11MB/sec anyway.


What I'm wondering is what could be causing this limitation besides the two cables running through the wall? Is that the only thing that could be doing it? What is the best way to really test it out? Do I need to buy some kind of network testing device that tests throughput?

Please, any advice would be greatly appreciated, even if it's to tell me another forum I should post this on. I transfer HUGE amounts of data across this network, which is why I paid to have the wires run everywhere.

Thanks

-Derek
7 answers Last reply
More about gigabit network transferring 10mb speeds
  1. update... my three switches are different brands, one is linksys, one is dlink and one is trendnet
  2. You could have interference near the cables (power wires or something), could have bad connections at the dends causing errors. To start narrowing down things, you need to pretty much narrow down things as much as you can. You already checked on the same switch, so that's a start. Did you test with a direct cable connection to it? If yes, then start going one step further out. Conenct that switch to a particular room, test that room and a PC directly on the switch for speeds between them. Basically go through each possible combination of connecting them, one step at a time, sooner or later you will find where the issue is.
  3. check the port lights to see if they're getting 1gb or 100mb links.
  4. Well, according to the router one of them is getting a 1gb link... and that changes based on which cable i plug in, except regardless of what the link says it appears to only transfer at 11MB/sec.

    Are those lights reliable? Could that just mean they are operating right at the threshold of 100mb? How does the router determine that anyway?
  5. Can you plug a GB enabled PC/Laptop direct to either living/bed room wall port (taking the additional switch out of the loop)


    I suspect there is a link speed negotiation issue between the switches. Plugging direct to wall port as described above will verify your cabling, and prove/deny switch uplink speed problem. This can be especially true where you have a mix of switch makes/models.
  6. Ya I'm not sure why I didn't try that out already. I will do that hopefully tonight and see what happens.

    Does anyone know how the router decides which ports are running gigabit and which are running 10/100?

    I have been thinking about getting a bunch of similar cisco switches but damn those things are expensive. Will depend how this test comes out, wouldnt make sense to buy the switches if the cable in the wall is limiting the speed.

    Thanks
  7. I've had a similar problem with the cable connection to my E4200 router. I replaced the ethernet cable with a wireless network adapter (used the Cisco Valet), and, bingo, speed doubled to 20 Mbps. And, by the way, this slow connection was with a computer running Windows 7. Didn't have slow upload with Vista or XP.

    Of course, LinkSys totally didn't have a clue and left me hanging without any resolution. I figured it out by trial and error. Hope this information is helpful. Best, /Jacques/

    ------------------------------------------------------------------------------------

    derekmarch said:
    I have a home network setup the following way.

    Cable modem into cisco-linksys E4200. 2 of the ports going out from the router plug into the wall, where one goes to the master bedroom and one goes to the living room. Once it gets to the wall jack in each of those rooms it goes out to a gigabit switch. Each of those two rooms has a computer and a TV connected, and the living room as a blu-ray also connected to the switch.

    The third port going out from the E4200 router goes to another gigabit switch, which is connected to a couple more computers in that room.

    All of the cables are either cat5e or cat6. The long cables running through the wall from the server room to the living room and master bedroom is 24gauge 4pair cat5e, it was run by a general contractor.

    Now for the problem.

    When I transfer between any of the computers on the network as it sits I get 11MB/sec. I get that number by clicking more details on the file transfer. In the network tab of task manager it sits pretty consistently at 10%.

    If I move any of the computers to be connected to the SAME switch (i tested all 3) i can transfer around 60MB/sec.

    Based on this testing my initial instinct is to say that the cable running between the rooms is limiting the transfer speed. However the cable is cat5e and rated for gigabit. Neither of the runs are anywhere near 300ft long. Plus the consistency of the transfer speeds at 11MB/sec makes me think it's being clearly capped at 100base-T speeds as opposed to just slowing down due to interference of the cable.

    As a side note there is a place in the router that tells you the speed of each port. For some reason it has one of my ports listed as gigabit and the others listed as 10/100Mbps. The yellow 3 foot cable i have is listing as gigabit, when i swap it with another cable in the router it changes the gigabit port to the one this yellow cable is on, very odd, however regardless of whether the router says its gigabit it only transfers at 11MB/sec anyway.


    What I'm wondering is what could be causing this limitation besides the two cables running through the wall? Is that the only thing that could be doing it? What is the best way to really test it out? Do I need to buy some kind of network testing device that tests throughput?

    Please, any advice would be greatly appreciated, even if it's to tell me another forum I should post this on. I transfer HUGE amounts of data across this network, which is why I paid to have the wires run everywhere.

    Thanks

    -Derek
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