Dowloads slow on Wifi fast on Ethernet - Full Strength

Question

Dowloads slow on Wifi fast on Ethernet - Full Strength

Hi Community! Coming back to Apple products for the first time since my Dad's Mac IIcx. Picked up a used iMac 24" Core 2 Duo and did a fresh install of Lion with all updates.

Works great except:

I have a 12 mbps internet service down and 1.5 up.

On ethernet I get the whole thing both ways.

On Wifi I only get 2mbps down and 1.5 up but my connection has full strength bars.

My router is a trusty Linksys WRT54g updated with the latest firmware.

Ping times are 25ms for wither connecion type and browsing is snappy enough. I am using the same OpenDNS DNS servers for all of my LAN clients.

As a matter of comparison, my iPhone 4 gets 12 and 1.5 sitting right next to my machine (same DNS).

So its something between the machine and router and it's not DNS since it is a download/upload wifi speed issue only.

All help appreciated!

Steven

iMac, Mac OS X (10.7.2), Core 2 Duo 2.6GHz 3GB RAM

Posted on Jan 12, 2012 6:47 AM

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Answer 1

Shane@TW

Level 1

0 points

Jan 12, 2012 7:28 AM in response to iWillNotEatGreenEggsandHam

When doing a technical assessment, I will recommend you to get rid of everything that is not necessary. That means the OpenDNS service.

The first thing I will do is to connect by LAN and test the network speed to see if it is a problem with WiFi or the software on Mac.

If you get the full speed with LAN (or if you can't perform LAN test), make sure you have only one device connecting to the router, so there is no disturbance.

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Answer 2

Jan 12, 2012 7:52 AM in response to Shane@TW

Shane,

Thanks for the help. As mentioned, this is fresh install of Lion and ran the iMac using the same router for ethernet and wifi which gave the very different results indicated in the post. The iPhone right next to it using the same Wifi recorded full speed 12 mbps down and 1.5 up using Speedtest.net app.

The iMac got 2mbps down and 1.5 up using Speedtest.net website immediately following the iPhone run.

The both used the same DNS servers. Plus, for download speed, I do not think DNS is a factor.

The iMac is handling the Wifi differently than the iPhone.

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Answer 3

Paul_31

Level 6

14,160 points

Jan 12, 2012 8:02 AM in response to iWillNotEatGreenEggsandHam

Have you tried experimenting with changing channels on the router? Also, what wifi encryption are you using WPA2 is preferred and apparently Macs don't like WEP (as well as it being insecure).

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Answer 4

Jan 12, 2012 8:49 AM in response to Paul_31

Sorry Paul. I forgot a few things. The Wifi is WPA2. I guess I can not edit the original post now.

here is what I have:

Wifi Security: WPA2

802.11b and g allowed

Channel should be fine as adjacent iPhone hits full speeds.

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Answer 5

Jan 12, 2012 8:49 AM in response to iWillNotEatGreenEggsandHam

I am thinking that the Mac might be connecting via 802.11b.

How can I check this?

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Answer 6

Jan 12, 2012 10:11 PM in response to iWillNotEatGreenEggsandHam

Update: Still the same problem. I went through all 11 channels on the Wifi Router after forcing it to only accept 802.11G connections. Channels 2 and 6 gave 4 mbps downloads while the rest were around 1 mbps. Better, but my iPhone 4 still gets the full 12 mbps sitting right next to the iMac

Any help appreciated.

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Answer 7

ppdawg

Level 1

0 points

Jan 20, 2012 8:59 AM in response to iWillNotEatGreenEggsandHam

i have the same problem. speed on my iphone and mac book from 2009 works great all the time. I have a 5 month old mac book pro and the internet speed goes from 11-12 mbps to 1-2 mbps every few hours. wifi connection in itself is strong though.... It's the internet speed that's messed up. Internet connection is good via ethernet.... Btw, I have at&t u-verse with the 2wire 3600hgv modem/router.

Let me know if you find a solution to this problem. THANX!!!

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Answer 8

Jan 20, 2012 9:10 AM in response to ppdawg

I fear this has something to do with their implementation. When I plug it into ethernet it's full speed. I've also noticed that since I put the iMac into my wifi, my overall wifi range and reliability has been reduced. Not sure if there is a relation but I have decided that I will run an ethernet to it and be done with it.

I have not found a solution or any ideas to try here.

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Answer 9

Feb 7, 2012 10:05 PM in response to iWillNotEatGreenEggsandHam

I want to conclude this thread by ending with that I never found a solution. I changed the routers to DD-WRT and still got slow/broken speeds (2-4 down, 1.2 up) with full wi-fi bars. There is something wacky with Apple's implementation of Wifi on my machine. Again, my iPhone 4 right next to it got full speed (12 down and 1.5 up) And this was a clean install of Lion. I ran an ethernet cord and I am at full speed. Too bad there is not a lot of info on this.

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Answer 10

Feb 7, 2012 10:08 PM in response to Paul_31

Yes, WPA2, thanks.

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Answer 11

Jul 12, 2014 9:15 AM in response to iWillNotEatGreenEggsandHam

Hello,

on an IMac you can use 'wireless diagnostics' app to investigate problems.

you may need to find it via spotlight / finder.

more inf:

About Wireless Diagnostics

mvg

Wilfried

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