Slow Wireless on my iMac

Hello,

The problem:
The airport of my imac, running osx 10.5.8, seems to have a problem. It is connected wirelessly, via a D-link 2.4Ghz router, to the internet. But the internet runs slowly. Sometimes more slowly than other times. Sometimes the internet connection seems to just get dropped, although it still shows full bars, and it takes a lot of patience or the turning-off-then-on of the airport to resume.
The imac is fully updated.

What I don't undestand:
I also have a macbook, running osx 10.5.8, and I don't have any problems with its wireless connection and speed. Even when I put the macbook right next to the imac, side by side, the macbook's internet speed is much better. Both with firefox or safari. The airport settings of the imac and macbook are identical. The DNS settings are the same.

What I've tried:
I tried switching to the open DNS addresses, and that has helped a bit, but the imac still lags behind the macbook and connection is still sometimes dropped or just horrible.

What I suspect:
When I bought the imac, it came with osx 10.5.6. Later I upgraded to 10.5.8. When I was on 10.5.6 I used a cable connection to the internet, and I only tried going wireless after the upgrade. So I can't say for sure whether something got screwed up in the upgrade, but I suspect that's the case from my reading of the experiences of others which I found through google.
My macbook pro was bought with 10.5.8 pre-installed.

What I need:
I would like the wireless speed of my imac to match my macbook's. I can't get a cable for the imac.

Thanks

Moved to correct forum.

Why can't you attach an ethernet cable to your iMac from your router to test with? You need to do that to see if the problem is software or hardware related. If when connected via ethernet the speed returns to normal, that might indicate a failing or bad airport card in your iMac.

how far away is the imac from the router? is your house made with heavy brick walls or anything that could block the wifi signal? i have the same problem, and my macbook connects side by side. but mine is due to the router being further away.

i have kind of concluded its due to the difference in engineering, seeing as the airport card is in a different place on both machines.

have you tried moving the imac closer?

Hi, I don't want to Hijack the trade, but I have the same problem I think, maybe I can help by providing a bit more info.

Cpu : IMAC 2010 3.06
Version 10.6.6.

Browsing on the internet : from slow to extremely slow, depending on web site and apparently computer's mood.
Streaming media : nearly impossible
Skype : bad connection but works.
Messenger (windows and Adium) : nearly impossible to connect, drops connection all the time.

However:
download speed is still good (downladed up to 600-700 kb/s last time I checked)
Wireless connection is full bars

Weird thing is, It was working perfectly before, just started doing that for 3-4 days now.

Tryed reseting the modem/rooter.
Tryed de-activating IPV 6 : helped a bit, could not connect at all to messenger before, now i can for a few mins.

I'm with Shaw cable.

Any ideas ?

Thanks

JP

My imac is in the room next to the router. Not that far and the door between the rooms remains open. But that should not be an issue because side by side my macbook performs much much better. I bought the imac in August 2009.

Nobody tried with wired connection? Please try and post the result. Maybe it's a good idea to assign a static IP which is different then the previous. Do you have Quality Of Service enabled on your router?

What you do not tell us is the model of your iMac. All G5 iMacs and a number of the early Intel models were only 802.11g Airport cards. Are you comparing speeds to a n card by chance?