Originally Posted by paxman
This problem has been around for quite a while but it isn't acknowledged by Apple. Here's a looong thread (watch out as this link crashes Safari on my machine) http://discussions.apple.com/thread....08143&tstart=0
Most people seem to be complaining that the problem started after they upgraded to 10.4.10 There are several threads like this one around on the mac related forums.
Again, most of those users are operating the OS on a Power Book or MacBook Pro, which is composed of Aluminum. Aluminum deteriorates the WiFi signal of the Airport card. As an example, I've owned a Mac Pro, first a quad and now an 8 core unit, and a Power Book G4, a MacBook and a MacBook Pro. I placed all four units in various scenarios at the same place/distance as my Mac Pro. The champion in all scenarios was the MacBook, my new MacBook Pro (late 2008) did better than my mid 2008 MacBook Pro, and my Power Book G4 performed the least favorably. I can state with confidence that the issue relates to the aluminum encasing interfering with the WiFi devices (the Airport cards in Power Mac G5's and Mac Pro's are located in a perforated section of the enclosure, hence the lack of general interference).
As per the statements that WiFi issues were fine in one revision but less improved in another, anecdotal at best. Unless all instances of said WiFi inoperability occurred in exactly similar situations and were documented precisely (as in a controlled experiment), more often it is a perceived notion rather than the actuality. As most people remember occurrences of inoperability (rather than always being aware of every second your system is actually functioning), most instances are exaggerated and inaccurate. Gripes about WiFi instability in Mac OS X have been around for years, and in almost all cases they have been associated with portable Pro units. I would certainly believe that if this was a wide spread issue that Apple could test empirically it would have been addressed years ago. I do believe Apple has improved the WiFi issue in relation to Pro portables with the late 2008 revision (the first revision of across the board portable systems since the Power Book G4) by placing the Airport Card within the aluminum enclosure that best suits radio frequency contact. Otherwise, as other commentators have stated, other factors such as access points, routers and their firmware, local radio interference (most people do not realize that even cordless phones operating on different channels may negatively impact WiFi reception), etc. are almost always to blame. I can not count how many times I've had to flash the firmware of Linksys routers (the worst router in my opinion) or simply trashed them and recommended clients to purchase an Apple unit. Granted, they are more expensive than most commercial quality routers, however they outperform most other units and have less conflicts, especially with Windows OS.
(I forgot to mention the new iMac's have aluminum as well, but in small amounts as the back of the unit is aluminum free)
... as an aside, and I mean no offense paxman, I've noticed by your comments you seem to be experiencing quite a few problems with your systems. What hardware are you using and in what situations do these problems persist?