russthered

Q: Unable to get 1000base t ethernet on iMac

My ISP has upgraded my internet connection to 200Mbps.

 

All I could get was +/-85Mbps. 

 

On checking my Network settings I found the ethernet set to "automatically detect' with all other settings greyed out but speed was 100base tx.

 

Selecting "manual" and selecting "1000base t" causes it to disconnect and give the "Cable Unplugged" alert.

 

Rebooting doesn't help.  I have correct cables.

 

How do I get it to change to 1000base t?

 

TIA,

 

Russ

 

Hardware Info:

 

Mac (21.5-inch, Mid 2010)

 

Broadcom 5764-B0:

 

  Name: ethernet

  Type: Ethernet Controller

  Bus: PCI

  Vendor ID: 0x14e4

  Device ID: 0x1684

  Subsystem Vendor ID: 0x14e4

  Subsystem ID: 0x1684

  Revision ID: 0x0010

  Link Width: x1

  BSD name: en0

  Kext name: AppleBCM5701Ethernet.kext

  Firmware version: 5764m-v3.38, 0x56cdb6d5

  Location: /System/Library/Extensions/IONetworkingFamily.kext/Contents/PlugIns/AppleBCM570 1Ethernet.kext

  mDNS offload capable: 10:9a:dd:4b:77:5d

  Version: 10.1.11

iMac 21.5", Mac OS X (10.6.6)

Posted on Dec 3, 2015 7:57 AM

Close

Q: Unable to get 1000base t ethernet on iMac

  • All replies
  • Helpful answers

  • by babowa,

    babowa babowa Dec 3, 2015 8:35 AM in response to russthered
    Level 7 (32,009 points)
    iPad
    Dec 3, 2015 8:35 AM in response to russthered

    I can't answer your direct question as my late 2012 iMac does show 1000base (greyed out); however, just in general, you do not always get the advertised speed (most of the time, they claim "up to xxxx", but do not guarantee it.  I used to pay Comcast for an advertised 25 mbps, but rarely got more than 5 or 6 (sometimes less than 1 mbps!) - their cables in this area are about 35 years old and there are at least 900 neighbors on one node so, if everyone happens to be surfing at the same time, the speed went down considerably. They may have newer/fiber cables to their node, but not from there to this area and/or we are too far away from the node. I now have VDSL - never going to be super fast, but at least I get what I pay for as I am the only customer using that line. Just some food for thought.

     

    And, did you get a new modem/router to be able to process faster speeds?

  • by russthered,

    russthered russthered Dec 3, 2015 8:46 AM in response to babowa
    Level 1 (0 points)
    Dec 3, 2015 8:46 AM in response to babowa

    Yes they sent new router, it's a rebranded Netgear with gigabit ethernet.

     

    I have a fibre optic connection and have always got what it says in the tin.

     

    Thanks for your interest.

  • by woodmeister50,

    woodmeister50 woodmeister50 Dec 3, 2015 9:34 AM in response to russthered
    Level 5 (5,510 points)
    Mac OS X
    Dec 3, 2015 9:34 AM in response to russthered

    First, how are you determining this internet connection speed?

    If you are using the Speedtest.net site, try a different server.

    The speeds can sometimes vary dramatically.

     

    I have Comcast Blast service (150MBit advertised) and I will get anywhere

    from a paltry 30MBit to 136MBit depending on the server used at Speedtest.net.

     

    Also, are you sure you are actually using ethernet because the speed just looks suspiciously

    like high speed WiFi.

  • by russthered,

    russthered russthered Dec 3, 2015 9:58 AM in response to woodmeister50
    Level 1 (0 points)
    Dec 3, 2015 9:58 AM in response to woodmeister50

    Yes, using ethernet. WiFi off.

     

    Yes, tried a couple more, all much of a muchness +/- 87Mbps

     

    I think the problem is either the ethernet card in the iMac or an OS problem.(or both)

  • by dwb,

    dwb dwb Dec 3, 2015 10:45 AM in response to russthered
    Level 7 (24,152 points)
    Notebooks
    Dec 3, 2015 10:45 AM in response to russthered

    Problem could be the cable. You’ll need a Cat 5e cable and if your cable run takes the cable near interference points - along electric wire runs, near electric motors, etc you can quickly lose speed. Lots of cables labeled Cat 5 and Cat 5e are cheaply made with insufficient insulation. Assuming you are getting true optical speeds into the house (have you checked with your iSP?) the problem could be anywhere from the cable leading into the house to the computer. At one point I had to have TimeWarner come to the house in a series of 4 frustrating visits to replace every bit of cable from the box outside the house and all through the house before I got my “free upgraded service” speed. The house had originally been serviced in the late 70s with additional runs added to bedrooms etc over the years.

  • by russthered,

    russthered russthered Dec 3, 2015 1:08 PM in response to dwb
    Level 1 (0 points)
    Dec 3, 2015 1:08 PM in response to dwb

    I have Cat 5e, it's only a 10' run under floor boards.

     

    I've been onto Support Chat and they want me to run Apple Hardware Test on run up.

     

    They say it should detect 1000base card in System Pref>>Network>>Advanced>>Hardware tab, but it's not.

     

    Will try it tomorrow, I have an awful feeling the card isn't capable of gigabit ethernet, even though advertised as such when I bought the iMac unit.

  • by tlb5736,

    tlb5736 tlb5736 Jul 23, 2016 5:53 PM in response to russthered
    Level 1 (8 points)
    Jul 23, 2016 5:53 PM in response to russthered

    I'd be curious to hear whether there were any other steps to try. I have a mid-2010 iMac as well. Service is at 50-60 mbps on my work PC but move the ethernet cable to my iMac and it only returns 21 mbps range. Same Broadcom 5764-B0 card although my network settings do show 1000base t. Wireless turned off. Cat 5e cable. Advice or tips are welcome. Thanks.