7 Replies Latest reply: Oct 10, 2011 3:55 PM by Abrehn
MikeeBee8 Level 1 (0 points)

Hi all,


Apologies for the vague subject. In a nutshell, my personal MacbookPro's internet is painfully slow loading over wireless. Its a 2008 17" 2.5GB Core2 Duo this is my network card according to 'about this Mac'



Card Type: AirPort Extreme  (0x14E4, 0x8C)

Firmware Version: Broadcom BCM43xx 1.0 (

Supported PHY Modes: 802.11 a/b/g/n



My router only supports 'g' (my Mac is 'n' capable). I'm quite far away from the router (it's fine when I'm near) this would be ok but my company Macbook Pro (similar spec except its a Unibody) works fine. I've recently re-installed Snow Leopard to see if there if that would fix it. It's like this regardless if I have no other apps open etc. Also my wirleless signal is full.


Basically I'm baffled, if there is anyway I can test/diagnose why this is happening?


Many thanks


  • Tesserax Level 9 (50,586 points)

    You mentioned that your MacBook Pro seems fine connected wirelessly when close to the router, but not when "quite far away."


    As you can imagine, not all Mac models use the same antenna or have the antenna placed in the same location within the body of the laptop.


    It sounds like the signal quality from the wireless router is just not adequate enough to provide enough bandwidth to your MacBook Pro. One way to measure signal quality is to calculate the Signal-to-Noise Ratio (SNR) of the router at the locations you typically use your MBP. You will want the SNR value to be 25+ dB at these locations to get decent bandwidth.


    SNR (in dB) = Signal (in dBm) - Noise (in dBm)


    You can easily find the Signal and Noise value using System Profiler on your MBP.


    ref: Click on the Apple icon on the menu bar > About This Mac > More Info... > Contents > Network > AirPort > Interfaces > en1 > Current Network Information > Find your wireless network > Signal / Noise


    While your still in the System Profiler, note the value for Transmit Rate.


    These values should be negative numbers. For example, mine currently read: -67 dBm / -95 dBm, with a transmit rate of 27 (Mbps). Plugging in these numbers yield: SNR = -67 - (-95) = 28. My Mac Mini is about four rooms away from my AEBS with about five walls between them. As you can see, the signal is still quite useable ... but the bandwidth is minimal, especially for streaming.


    SNR Guideline

    • 40dB+ SNR = Excellent signal
    • 25dB to 40dB SNR = Very good signal
    • 15dB to 25dB SNR = Low signal
    • 10dB to 15dB SNR = Very low signal
    • 5dB to 10dB SNR = No signal

  • MikeeBee8 Level 1 (0 points)



    Thanks for such a detailed response. My signal/noise is


    Signal / Noise: -76 dBm / -94 dBm SNR = -76 - (-94) = 18

    Transmit Rate: 24


    But was...


    Signal / Noise: -81 dBm / -88 dBm SNR = -81 - (-88) = 7

    Transmit Rate: 18


    I am unable to move the router or my workspace so what would you suggest? Would an 'n' enabled router help?


    Many thanks


  • Tesserax Level 9 (50,586 points)

    Before investing in another router, I would take your MBP to different locations where you can connect to other Wi-Fis. Do the same SNR calulations that these locations to get an idea on how your MBP's wireless performs. If you see definitive improvement, getting a new router for your network may well be worth it. If not, then there may be something amiss with the MBP and a trip to the Apple Store would be warranted.

  • MikeeBee8 Level 1 (0 points)



    I tested the signal/noise ratio on the MBP that is fine on the internet and the result is very similar to the MBP that is struggling. Could that indecate a fault with the Airport antenna? I've got a signal booster coming today from my ISP so I'll see how that goes.



  • Tesserax Level 9 (50,586 points)

    Possibly. Please post back your results with the signal booster.

  • MikeeBee8 Level 1 (0 points)

    How rude of me! I was just popping back to this thread to see about transmit rate values and realise I didn't respond.


    I put the signal booster half way between my router and my Mac which was at the top of the house.


    Worked good for a while (S/N was hovering around 15-25) but recently (unsure of the reason) it has been much slower. Just before calling the ISP I tried putting the signal booster in the same room as my Mac. Now I have...


    Signal / Noise:          -61 dBm / -91 dBm

    Transmit Rate:          54


    This was only 10 minutes ago but it seems good. I have no idea why I didn't do this earlier!


    Many thanks

  • Abrehn Level 1 (0 points)



    That was an excellent suggestion. My MacBook Pro is running slow. With your suggestion I was able to determine that I had a low signal. Plus, I learned alot. Very helpful.


    I am going to assume that the low signal is the source of my problem. I have done lots of cleanup etc., so I think I am ok on that end.