Network speed on MBP caped at 20Mbit.

Discussion in 'MacBook Pro' started by JulianY, Jul 16, 2010.

  1. JulianY macrumors newbie

    JulianY

    Joined:
    Jul 16, 2010
    #1
    My network speed on my MBP is being caped at 20Mbit. This happens on both wifi and and wired. My isp provides 80Mb and other machines on the network can run speedtest.net test in excess of 70+

    I have tried everything i can fin including disabling IPv6, open DNS, manual setting the MTU etc etc. but nothing seems to change it

    I am using a WNDR3700 router. I have tried disabling n band and only running g , switching of 5Ghz , switching of 2.4ghz no change. however the fact that the choke is there also on the wired network leads me to believe its not this.

    I have also tried taking the router out of the equation and connecting directly to the cable box. same thing 20Mb cap

    i would be great-full for any suggestions

    Julian
     
  2. chachawpi macrumors member

    Joined:
    Feb 7, 2009
    #2
  3. winninganthem macrumors 6502a

    winninganthem

    Joined:
    Jun 10, 2008
  4. JulianY thread starter macrumors newbie

    JulianY

    Joined:
    Jul 16, 2010
    #4
    chachawpi thanks for the iperf tip, but i am now even more confused :confused:

    on WIFI to windows server
    Code:
    julian-youngs-macbook-pro:iperf-1.7.0-powerpc-apple-darwin6.4 julian$ ./iperf -c 192.168.2.10
    ------------------------------------------------------------
    Client connecting to 192.168.2.10, TCP port 5001
    TCP window size:  129 KByte (default)
    ------------------------------------------------------------
    [  3] local 192.168.2.101 port 55533 connected with 192.168.2.10 port 5001
    [ ID] Interval       Transfer     Bandwidth
    [  3]  0.0-10.0 sec  94.6 MBytes  79.2 Mbits/sec
    
    on cat5
    Code:
    ------------------------------------------------------------
    Client connecting to 192.168.2.10, TCP port 5001
    TCP window size:  129 KByte (default)
    ------------------------------------------------------------
    [  3] local 192.168.2.104 port 55538 connected with 192.168.2.10 port 5001
    [ ID] Interval       Transfer     Bandwidth
    [  3]  0.0-10.0 sec   111 MBytes  92.8 Mbits/sec
    
    

    However using the MBP as a server :confused:
    on wifi
    Code:
     on wifi
    julian-youngs-macbook-pro:iperf-1.7.0-powerpc-apple-darwin6.4 julian$ ./iperf -s
    ------------------------------------------------------------
    Server listening on TCP port 5001
    TCP window size:  256 KByte (default)
    ------------------------------------------------------------
    [  4] local 192.168.2.105 port 5001 connected with 192.168.2.10 port 1478
    [ ID] Interval       Transfer     Bandwidth
    [  4]  0.0-10.0 sec  35.0 MBytes  29.4 Mbits/sec
    [  4] local 192.168.2.105 port 5001 connected with 192.168.2.10 port 1479
    [ ID] Interval       Transfer     Bandwidth
    [  4]  0.0-10.0 sec  41.4 MBytes  34.7 Mbits/sec
    [  4] local 192.168.2.105 port 5001 connected with 192.168.2.10 port 1480
    [ ID] Interval       Transfer     Bandwidth
    [  4]  0.0-10.0 sec  27.8 MBytes  23.3 Mbits/sec
    [  4] local 192.168.2.105 port 5001 connected with 192.168.2.10 port 1481
    [ ID] Interval       Transfer     Bandwidth
    [  4]  0.0-10.0 sec  39.3 MBytes  33.0 Mbits/sec
    [  4] local 192.168.2.105 port 5001 connected with 192.168.2.10 port 1482
    [ ID] Interval       Transfer     Bandwidth
    [  4]  0.0-10.0 sec  37.2 MBytes  31.2 Mbits/sec
    [  4] local 192.168.2.105 port 5001 connected with 192.168.2.10 port 1483
    [ ID] Interval       Transfer     Bandwidth
    [  4]  0.0-10.0 sec  32.3 MBytes  27.1 Mbits/sec
    
    and on cat 5

    Code:
    julian-youngs-macbook-pro:iperf-1.7.0-powerpc-apple-darwin6.4 julian$ ./iperf -s
    ------------------------------------------------------------
    Server listening on TCP port 5001
    TCP window size:  256 KByte (default)
    ------------------------------------------------------------
    [  4] local 192.168.2.106 port 5001 connected with 192.168.2.10 port 1505
    [ ID] Interval       Transfer     Bandwidth
    [  4]  0.0-10.0 sec  67.7 MBytes  56.8 Mbits/sec
    [  4] local 192.168.2.106 port 5001 connected with 192.168.2.10 port 1507
    [ ID] Interval       Transfer     Bandwidth
    [  4]  0.0-10.0 sec  68.4 MBytes  57.3 Mbits/sec
    
    
    
    but using speedtest.net

    From my MBP
    [​IMG]

    From my desktop
    [​IMG]

    not sure how to interpret the results but it look to me like i have a choke on incoming data some how :mad:
     
  5. bigjobby macrumors 65816

    Joined:
    Apr 7, 2010
    Location:
    London, UK
    #5
    just checking but is your ethernet settings on the MBP set to 1000baseT?
     
  6. JulianY thread starter macrumors newbie

    JulianY

    Joined:
    Jul 16, 2010
    #6
    no its set to 100 because i don't have a gig switch yet
     
  7. akramer macrumors member

    Joined:
    May 20, 2010
    #7
    I have a similar issue, though not identical. When accessing the internet over wireless, I can't get past 20mbps. To other machines on the same subnet, I can. Wired works fine.

    Via ethernet:
    MBP->speedtest.net: 60mbps down
    G5 tower->speedtest.net: 60mbps down

    Via 802.11N network
    MBP->G5 (tower is wired): 90mbps down
    MBP->speedtest.net: 20mbps
    MBP->G5->speedtest.net (using ssh -D socks proxying through the G5 to get to speedtest.net): 60mbps down


    As far as I can tell, OS X does something "different" with either individual packets or TCP connection options going to a remote network. Over wireless I can access other machines on the same network at near 100mbps. As soon as I hit something on the internet, 20mbps. It's interesting that we're seeing the same value.


    I've spent hours troubleshooting this. I could not figure it out. Both my fall 2008 unibody and spring 2010 unibody exhibit the exact same behavior. I've looked at packet traces, connections both wired and wireless look identical: both have window scaling enabled set to the same values, and sack enabled.

    I've tried playing with the following sysctl variables:
    net.inet.tcp.slowstart_flightsize
    net.inet.tcp.local_slowstart_flightsize
    net.inet.tcp.recvspace

    I've had no luck. If anyone has insight into this, please let me know!
    The most telling thing is that a connection proxied through a machine on the same subnet works fine. That's the most bizarre part.
     
  8. RedReplicant macrumors 6502a

    Joined:
    Mar 31, 2010
    #8
    I consistently pull 55MB/s (440mbit) on mine, you have a network setup problem.
    I also don't use wireless though, so..
     
  9. akramer macrumors member

    Joined:
    May 20, 2010
    #9
    Are you replying to me or the OP? My machine works fine connected to gig ethernet - I did not test local transfer speeds over wired ethernet, what's the point? I know that works properly.

    The OP only has a 100mbit switch, so obviously he's not going to get transfer rates of half a gig.
     
  10. akramer macrumors member

    Joined:
    May 20, 2010
    #10
    This speedtest was done over wireless, not wired, right?
    Can you try this with a cat5 cable plugged into your machine and airport disabled?
     
  11. RedReplicant macrumors 6502a

    Joined:
    Mar 31, 2010
    #11
    I wasn't talking LAN transfers either.
     
  12. JulianY thread starter macrumors newbie

    JulianY

    Joined:
    Jul 16, 2010
    #12
    yes on wifi , hear you go on cat5 as requested

    [​IMG]
     
  13. RedReplicant macrumors 6502a

    Joined:
    Mar 31, 2010
  14. elvisidal macrumors member

    elvisidal

    Joined:
    Jul 13, 2010
  15. JulianY thread starter macrumors newbie

    JulianY

    Joined:
    Jul 16, 2010
    #15
    I would but the problem is i am paying for it :mad:
     
  16. JulianY thread starter macrumors newbie

    JulianY

    Joined:
    Jul 16, 2010
    #16
    @akramer

    The proxy thing, seems to confirm what i am seeing, the bandwidth loss is when you leave the LAN.

    Out of interest what router are you using? I am just wondering about going down the apple store , telling them the story and getting an Airport Extreame to be returned if it does not fix the problem.

    JY
     
  17. akramer macrumors member

    Joined:
    May 20, 2010
    #17
    I have a Netgear WNR3500L running Tomato.
     
  18. JulianY thread starter macrumors newbie

    JulianY

    Joined:
    Jul 16, 2010
    #18

    I just wonder if osx detects netgear and dumbs down ?

    sounds crazy, but i am struggling for another explanation

    J
     
  19. akramer macrumors member

    Joined:
    May 20, 2010
    #19
    My speeds from one machine to another over the same wireless router are fine, it's only when accessing the internet. I can't see how it could be related to the vendor of the wireless AP.

    I think it might be related to interface speed - my WNR3500L has a gigabit switch, on which my MBP works fine. You're plugging into a 100mbit switch. I'll try wired at 100mbps later to see if I'm capped at 20mbps from the internet.
     
  20. JulianY thread starter macrumors newbie

    JulianY

    Joined:
    Jul 16, 2010
    #20
    My router is gigabit, but my switch in this room is not.I have a replacement on order. My reasoning is every time i find some one with a similar problem statistically its a ne gear rooter.

    I have tried connecting the MBP to the cable modem which is gigabit and that makes no difference, which I admit goes against the above

    I am totally lost with this one

    J
     
  21. bigjobby macrumors 65816

    Joined:
    Apr 7, 2010
    Location:
    London, UK
    #21
    ... You're not the only one.

    I'm following this thread with intrigue but I'm curious if this bandwidth problem is just restricted to port 80 and would it also occur with Windows running under bootcamp? Not trying to say get Windows installed but if anyone else having similar problems and has already tested against this setup, a response would be nice. Just trying to establish whether its an OS or hardware issue. Saying that, lets see what happens when you get your switch changed.

    Best of luck.
     
  22. elvisidal macrumors member

    elvisidal

    Joined:
    Jul 13, 2010
    #22
    i'm using a netgear DG834G.
    It'd be interesting to see if it was an issue with netgear as i am looking to upgrade soon to something with wireless N
     
  23. Leet Apple macrumors 6502a

    Leet Apple

    Joined:
    Nov 10, 2009
    Location:
    Canada
  24. ozreth macrumors 65816

    ozreth

    Joined:
    Nov 5, 2009
    #24
    Hm.

    My download speeds are terrible so I ran this test. I have the 20 dollar cox plan which is 3mbs (horrible I know) and my speedtest is showing my download speed at 1mbps.

    This normal?
     
  25. chachawpi macrumors member

    Joined:
    Feb 7, 2009
    #25
    I do see similar speeds, but I have a 22/1 connection so I guess I couldn't get any higher either way.

    [​IMG]

    Try sticking a router between two of your computers to test the WAN theory.
     

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