Why is my core i7's wifi so slow? Tried multiple fixes

Discussion in 'iMac' started by aneftp, Feb 27, 2010.

  1. aneftp macrumors 601

    Jul 28, 2007
    My core i7's wifi has been acting up like crazy the past couple of days.
    I had the same wifi issue with my previous iMac alumn 2.4 and my macbook 2.4

    Wifi speeds are so sporadic. One minute it's super fast. Another it slows to a crawl. When plugged directly into ethernet, it's always fast. I moved my router right next to the iMac so it's not a signal issue. But I prefer it to be in another room since I use slingbox with my cablebox.

    I've research this issue. This is a known Apple problem. Why hasn't Apple fully address the slow wifi issues. My Sony Vaio laptop and Gateway Laptop connects to my wireless network anywhere in the house without any issues.

    I've tried changing the channels (default is 6) to channel 11 or 1. This helps for a while than the internet slows down again. Same thing with changing the DNS.

    It's not my router. I tried the Netgear, Linksys and my old Belkin router. It's on WPA2.

    I'm a techie (had one of the original Linksys routers way back in 2000) so I know my routers.

    What's Apple's problem? Any other suggestions for me? I am very dumbfounded.

    Hey at least my iMac core i7's screen appears perfect and it's quiet the majority of the time...but wifi sucks at this point. I doubt it's a hardware problem either since it does work from time to time.
  2. aneftp thread starter macrumors 601

    Jul 28, 2007

    104 Views on this topic and no responses.

    I called Apple tech support. While he was courteous, he wasn't helpful. He tried to blame my ISP (cable internet), tried to blame my router (I told him I used 3 different routers; they all couldn't be defective cause my Windows PCs all work fine).

    I highly doubt this is a wifi hardware issue since the problem comes/goes. It has to do something with Apple's OS. It's not like this is a new problem. I am just stuck at this point.

    I can't even upload a 300MB file to my Mobile Me to keep as storage. It loads 20MB craps out, than tries to load 50MB and than craps out. Very frustrated at this point.
  3. xSPRINTERx macrumors regular

    Dec 14, 2009
    I was having major issues with m macbook and my :apple:time machine.

    This is what I did to fix it.

    Turn off Airport on your imac. Go to "open network preferences" click in advanced and delete all of the networks in the list once done click o.k and apply.

    Leave airport turned off.

    Go into your keychain in utilities.

    once key chain is open, type "airport" into the keychain search box. Delete everything in the keychain to do with airport.

    Once done close keychain.

    Open a finder window.

    Go to your mac's HD.

    Find the library folder and enter it.
    Then find preferences and enter it.
    Find "systemconfiguration" and enter it.

    you will now have 7 files in this folder.

    delete the following (don't worry they rebuild when you reboot the mac)


    once these are deleted. reboot the Mac.

    Once rebooted switch on airport and find your network.

    This worked for me, hope it does for you.
  4. stridemat Moderator


    Staff Member

    Apr 2, 2008
    Does it just happen to the i7? What about other computers that are connected via WiFi?
  5. djc6 macrumors 6502a

    Aug 11, 2007
    Cleveland, OH
    Try Bootcamp? that should narrow down if its a hardware/software issue.

    If you see an intermittent connecting in windows as well, its almost certainly hardware (imac/router/modem/etc).
  6. MacHamster68 macrumors 68040


    Sep 17, 2009
    thats why i still prefer ethernet , no problems whatsoever
  7. aneftp thread starter macrumors 601

    Jul 28, 2007
    I have Windows 7 Professional with Bootcamp. Wifi Internet Speeds are fast and consistent. Speedtest.net always is around 9 MB/s download.

    With Snow Leopard on my iMac there speeds are very inconsistent. Sometimes I get the 9MB/s on it. Sometimes speedtest.net doesn't even complete and gives with an error message.

    This has got to be a snow leopard problem. I'm researched these forums and google apple's tech support site. Multiple people have had issues after Tiger 10.4.10 with intermittent wifi speeds.

    I don't mind using Bootcamp with Windows until I get the problem solved. In fact I'm typing using Windows 7 bootcamp right now. But Bootcamp has issues itself (first the dreaded black screen on install; fixed that, than I had no audio, fixed that). Now I have a screen gradient problem. Must be an issue with the ATI video driver.

    I have the "perfect" iMac core 7 (very little noise, screen is flawless). Now even only I can fix this wifi problem. The bootcamp problem with the screen gradient I can try to live with or I'll just install Windows XP. I'll try what the other poster said with changing the configuration. Hopefully that works.
  8. xSPRINTERx macrumors regular

    Dec 14, 2009
    Let me know if it worked. I can not claim the fix, i found it after doing loads of searching.

    My network (mac book) has been fine ever since. My mac mini & my wife's windows pc had no issues at all with connection. I have all 3 machines next to each other and he only one that would drop was the macbook.

    Its been solid for about a week and half.
  9. aneftp thread starter macrumors 601

    Jul 28, 2007
    Tried your solution. It didn't work. Very annoying. WiFi is still so sporadic. It starts and stops. Currently speedtest.net can't even complete the speedtest.

    So changing DNS doesn't help. Changing wifi channels to 11 or 1 doesn't help. And changing my wireless routers didn't work.

    I have 2 options:
    1. Run Bootcamp all the time with Windows 7 (that's fine but I've got bootcamp issues with the grainy screen ATI/video driver problem).
    2. Run ethernet straight. Again, I have the cable modem/router setup on the other side of the house because I run slingbox/and my security system for the house is configured for that phone outlet on that side.

    This has been a known Apple issue for the past 2 1/2 years (since Tiger 10.4.10). I am positive it's not a hardware issue (because it runs fine in bootcamp). It's gotta be a software issue.
  10. xSPRINTERx macrumors regular

    Dec 14, 2009
    I'm sorry it didn't work.

    I have no idea what it cold be. When i had my problem with wifi, i did a lot of research and it clearly is an issue.

    hope you get it fixed.
  11. BulletToothTony macrumors 6502


    Jan 5, 2009
    what are your speeds?

    are you having problems only on your internet browswer or when you're downloading big files as well..

    i had a problem like that once, i re-installed firefox after erasing ALL the files and preferences related to it and it worked great..

    No offense but i don't think it's a "Snow Leopard" problem, or an OS problem for we would all have it.. and my speeds are 21mbps every single time..

    What exactly comes down to a crawl? web browsing? try a new browser like chrome or something.. try to narrow down your problem so u know how to fix it.. or if you don't just get it exchanged
  12. MacAndMic macrumors 6502

    Jun 4, 2009
    I think you need to look past the OS as being a source. It may seem obvious to you but do realize that there are millions of people on here running the same OS without issue?

    I understand you are a "techie". IMO a "geek" and respect your knowledge but sometimes you have to go back to the basics......maybe check your cables? You may be saying "I'm talking about wireless!" but there are still cables involved.

    How many times have you moved your wireless router to prove your theory from OS to OS? It just so happens it is connected to something right?

    I respect your "techie" labeling but I've been troubleshooting things like this forever as a career and if there is one thing I have learned is that is usually comes down to something stupid like a bad connection.

  13. aneftp thread starter macrumors 601

    Jul 28, 2007
    I'll just bear it for now the problems I'm having.

    Like I said, if I use bootcamp and Windows 7 in the iMac core i7, there's no issues at all with wifi. I don't mind using Windows 7 in bootcamp but I am having video graining issues with Win 7.

    And I have 3 other wireless routers sitting around I've been trying to troubleshoot. My other 2 windows pc laptops work fine will all 3 wireless routers.

    I'll go to Best Buy or Costco, try to pick a newer router and see if that helps solves my issues.

    But this is a common issue. Just google search "slow wifi" and macbook and iMac's and you see lots of people have been having these issues since Tiger 10.4.10 release and the problems continued onto leopard/snow leopard.

    My internet wifi speeds are sporatic. Sometimes I get a burst of 9 mb/s, other times it starts at 9 mb/s and literally slows to a crawl where it stops work. I can't even upload a 260MB file to mobile me because it will go halfway and just stop. If I am on Win 7/bootcamp the uploads work fine.
  14. lefse macrumors member

    Jul 11, 2008
    Apple's Airport Utility got an option called "Use interference robustness".

    I realize that you don't have an Apple access point, but maybe windows and your access point uses something like this when communicating...

    Do you have any wireless transmitters (phones etc. on in your house)? Maybe even a microwave oven...
  15. aneftp thread starter macrumors 601

    Jul 28, 2007
    I may pick up a Apple Time Capsule. $300 bucks seems steep to me. Trying to justify it. 1TB hard external hard drives costs around $100-150. Wireless routers costs between $50-100.

    Has anyone had wifi issues with Time Capsule? I know the newer ones have duo band that run stimulatanous vs. the older time capsule that made you choose.

    I've seen on Apple Discussion forms that people have had slow wifi (like me) even with the Apple Time Capsule.
  16. kbjerring macrumors newbie

    Mar 11, 2010
    Slow WiFi... continued

    I have similar problems with slow WiFi with my new iMac 27 i5. I'm switching from an iMac 24 and right now they are standing right next to each other, both running 10.6.2 - but my WiFi speeds differ a LOT. While my old iMac24 runs at about 16 Mbit I only get 6-8 Mbit on my new iMac27 ???? This is really annoying. And I'm using a TimeCapsule.
  17. islandbay macrumors newbie

    Apr 28, 2010
    Same here. My iMac i7 is sitting right next to my MacBook 2GHz C2D, both running 10.6.3 on the same wifi network from an Airport Extreme (802.11n). Right now speedtest.net is showing 6.35Mb/s on the MacBook and 0.71Mb/s in the iMac. It took 3 attempts to even complete the test on the iMac. It's the same speed problem in Firefox, Safari, iTunes, Google Notifier, you name it. Are there ANY real fixes to this issue or do I just have to rewire my house to get an ethernet cable to my wirelessless iMac?
  18. vansouza macrumors 68000


    Mar 28, 2006
    West Plains, MO USA Earth
  19. foxeh30 macrumors newbie

    Apr 29, 2010
    First post!

    I recently bought an i7. Very very very happy with it! Had PCs all my life but due to a job change decided switchin to a Mac would suit me better.

    I too experienced wayward wifi speeds. It would drop from 1meg a sec to like 22k a sec, it would then spike up and down all day.

    Tried all the fixes listed in this thread and the ones on multiple forums. Changing channel helped until the iMac went to sleep or I switched off. When the machine had booted back up the slow speeds would reappear.

    I had tried several routers too and my Win7 notebook works perfectly.

    Had almost given up and gone with trailing a 10 metre cable from the router to the iMac...until I decided to manually assign an IP for every device in the house. This included the two iPhones we have and the iTouch. I stuck the iMac on the first available address and then just added the rest after that one by one.

    Since then Ive had no problems what so ever! Ive logged off, restarted, switched off etc etc and when Ive tried resuming downloads its been running at full pelt. Also tried it whilst playin MW2 on the PS3 and the iMac still holds 1meg a sec speeds.

    It may work for you, may not but manually assiging each device an IP has solved my issues. Hope it works for you too!
  20. thekb macrumors 6502a

    May 8, 2010
    static IP

    Hey, tell me more about this procedure, please. I tried to do this but I am not sure I did it right ...

    The problem is my imac loses connnection to the router and I have to disable airport and reenable it to get a connection. I was having this problem with a wireless printer until I set a static IP for it and it has been rock solid ever since. This is very annoying!

    Do you think that would solve my problem?

  21. foxeh30 macrumors newbie

    Apr 29, 2010
    I just went into the admin panel for my Netgear router, searched for the attached devices and then assigned them an IP. If you have a netgear router drop me a PM and Ill walk you through how I did it.

    Has been two weeks since I have done the manually assigned IPs and its been flawless, no issues at all.
  22. Stealthipad macrumors 68040


    Apr 30, 2010
    My 27" iMac i7 is VERY fast on my Cisco Aironet. I returned my AirPort that was surposed to be faster but the Cisco beat it hands down.:eek:
  23. mindquest macrumors regular

    Oct 25, 2009
    I am going to try the static IP fix and see if it helps my i7 as well, will report back!
  24. willcodejavafor macrumors regular

    Dec 4, 2007
  25. mindquest macrumors regular

    Oct 25, 2009
    Static IP didn't work. :(

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