Internet really slow after upgrading to Lion from Leopard!

How would you explain then that my wife's iMac i5 (native Lion) using my linksys router works flawlessly with consistent 20Mbps downloads and my i7 since the upgrade from Snow Leopard usually operates at about 1/2 that speed? (it does fluctuate periodically from 10Mbps down to 6 and on rare occasions up to 16Mbps)?

Mark

PS - I do have an Airport Extreme that I haven't hooked up yet, so I will give that a try as well

Mark, I feel your pain, but hang in there. I experienced slowness after my Snow Leopard upgrade to Lion, but it eventually resolved itself.

Not sure which of the following helped, if any:

1) making sure all OS X updates are applied

2) clear your ~/Library/Caches folder (using a utility like OnyX can really help with cleaning up the system)

3) Adding 127.0.0.1 as a DNS server in your Network system preference panel.

4) Using DNS servers other than your ISP's. I use a mix of my ISP DNS and Google DNS.

Lion is capable of full network performance on an upgraded system, it's just a matter of trying things until the problem is resolved. If you get desperate, you could always do an Install and Restore.

Only two of six Macs had an Internet connectivity issue, so it does not appear to affect all computers

I'm experiencing something similar. both my Internet connections work poorly (LAN and wi-fi) but when I'm in recovery mode the Internet works fine. any ideas? I've tried most (if not all) of the suggestions.

other than clean install

I've increased the number of channels of the wi-fi router, speed seems better now.

The problem with apple is that they change things without advising all the 3rd parts who makes accessories, so that they have to be changed or replaced but only after 1000 people have found the bug...

Maybe all of us have a Belking router...we didn't specified it...

BTW @ Neurorad, I buy Mac because they work well, because I can work with them on my stuff and not work on them to do my stuff. Every single machine has to work well with an update, otherwise the update is ****.

If I master a DVD that doesn't work on 1 brand of dvd player, Sony throw it back to me with a FAILED QC.

It should be the same with an update of a operative system which should go on every possible mac.

and I don't think a clean install will solve the problem.

WHERE THE HECK ARE THE APPLE CUSTOMER ADVISORS, HIDING? WHY DON'T YOU WRITE A THING?

IT'S A PRETTY COMMON ISSUE NOW...

My wifi/internet speed went from 8mps to 0.1mps after upgrading to lion. On a whim, I uninstalled Norton programs, now it's running like a champ.

My iMac was horribly slow after the 10.7.2 update, but I believe I found the answer. I turned OFF all iCloud features EVERYTHING. Speeds are back to normal again. Try it.

Thanks for the tip. It worked for me. Once I signed out of iCloud (using system preferences) internet speed went back to normal again.

So the culprit was definitely iCloud for me.

This is a user-to-user forum. Apple advisers are not involved and shouting won't change that.

Uninstalling Norton is always a good idea. 😁

You'd really only know if iCloud was the culprit if things returned to slow again after re-enabling it. Turning off the iCloud features may have done something else that was the culprit, like purge a cache file or something.

iCloud is indeed the key to this question! I turned off photostream and wifi speed is back!

Leopard worked fine since lion same issue, bring back steve!