Disclaimer, in case you’ve reached this page after a Web search: In this article, I don’t offer answers or solutions. I’m writing this as a way to think aloud, share observations, and — why not? — look for input.

Up until Mac OS X 10.7 Lion, I usually installed a new version of Mac OS X shortly after its release. A new version of Mac OS X has always been an exciting occasion for me (I remember waiting in queue to purchase the box of 10.4 Tiger when it was released). But from 10.7 Lion onward, I’ve delayed the upgrade for days, even weeks. I installed Lion when version 10.7.2 was released. I installed Mountain Lion after the release of version 10.8.1. I installed Mavericks at version 10.9.0, but I waited at least one month before installing — I upgraded in late November 2013, and on December 16, version 10.9.1 was out.

Now, at every Mac OS X update, the Web is usually buzzing with first reactions and the like, and a fair amount of horror stories start appearing. Some users complain that the new OS X has broken certain functionalities in their systems, or has broken backward compatibility for specific applications or services they’ve been relying on, or has impacted their Mac’s performance in a number of ways, and so on and so forth. In the past, despite reading these stories and tales of woe, I used to upgrade my Mac to the new version of Mac OS X anyway, because — perhaps a bit arrogantly — I was convinced that my Mac wouldn’t be affected. As a power user, I was proud of the tidiness and organisation of my Mac OS X installation. I had never installed dubious software, especially hacks to alter how Mac OS X would look or work. So I was always eager to install the new OS X version because I had nothing to fear.

In recent years, however, I’ve grown wary of new OS X versions mainly because I’ve seen first-hand how they managed to cause problems even to users who, like me, kept their Mac OS X machines clean and perfectly fine-tuned with just the best-quality apps and tools. Still, after Mac OS X 10.6 Snow Leopard — which a lot of people still consider the last truly stable version of Mac OS X — despite my worries and my cautiousness, I’ve kept upgrading to the new version, and my experience has generally been positive, with two notable exceptions:

1. Starting with Mac OS X 10.7 Lion, the Wi-Fi performance of my Mac began an annoying downward spiral.
2. After upgrading from 10.8 Mountain Lion to 10.9 Mavericks, my Mac’s battery life got worse by approximately 45 minutes. (On a full charge under Mac OS X 10.8.5, my 2009 MacBook Pro could last about four hours. Under Mac OS X 10.9.0, in the same conditions, I never got past three hours and fifteen minutes or so.)

Over time, I’ve accepted the loss of part of my MacBook Pro’s battery life, but the Wi-Fi degradation is, to this day, the most aggravating issue.

Now, I know that my Wi-Fi home network is far from perfect. I’ve tried to set it up in the best possible way given the environment’s conditions (I can’t move the router or the AirPort base stations closer to my main Mac), but little has changed over the years, except the Mac OS X version on my MacBook Pro, so I’m fairly certain where to put the blame. Let’s get into this in more detail, you’ll let me know what you think.

Wi-Fi devices and configuration

• Cisco router in the living-room. The router’s Wi-Fi capabilities are similar to a 5th-gen AirPort Extreme base station (Wi-Fi 802.11a/b/g/n, ability to broadcast on 2.4 and 5 GHz frequencies, etc.)
• AirPort Express (802.11n) base station №1 connected via Ethernet to the router.
• AirPort Express (802.11g) base station №2 used to extend the range of base №1, positioned out of my studio’s door, in the hallway that connects the living area with the bedroom.

In my household, there are various devices connecting to the Wi-Fi network. The wireless clients that remain the most connected on a daily basis are:

• My main machine, a mid-2009 MacBook Pro (802.11a/b/g/n)
• A 12-inch PowerBook G4 and a 17-inch PowerBook G4 (802.11b/g)
• A Power Mac G4 Cube (802.11b)
• My wife’s 2008 Toshiba Satellite (802.11a/b/g)
• Two iPhones and two iPads (802.11a/b/g/n)

I know what you’re thinking: with this wireless setup and clients, especially the mix of the two AirPort Express base stations, the network is already compromised with regard to speed. The router is set to broadcast using the “802.11n (compatible with b/g)” option, and when using a 802.11n-capable device in the router’s proximity, things are really great.

Sure, the network’s speed could be better, and I hope it will be as soon as I replace the older base station with a newer one supporting the 802.11n protocol. But I’m not complaining about the network’s speed. Considering the varied setup and the fact that I live in a very busy neighbourhood, Wi-Fi-wise (when I pull down the Wi-Fi menu on my Mac, I can see no fewer than 30 other networks), things could be worse.

What I mean by ‘Performance degradation’

The performance degradation affects only the MacBook Pro, and it got worse from OS X 10.7 Lion onward. I’m referring to the ability of connecting to the home Wi-Fi network in a continuous, reliable way. When my MacBook Pro ran Mac OS X 10.6.8 four years ago, it was in the same place as it is now. Nothing has changed in the position of the router or the base stations or the Macs that connect to the network. But under Snow Leopard the MacBook Pro never dropped a connection unless there was something going on with the ISP and the router needed to be restarted. Not only that, but under Snow Leopard the connection speed was less ‘jumpy’ and more homogeneous. Under 10.7 Lion, the degradation wasn’t dramatic: just the occasional dropped connection. 

Things have got noticeably worse under Mac OS X 10.8 Mountain Lion and 10.9 Mavericks: the MacBook Pro starts dropping connections frequently and in unpredictable ways. Sometimes it is enough to leave the Mac idle for a while, and when the display sleeps as per Energy Saving settings, the Mac also disconnects from the Wi-Fi network automatically. (It’s not just me, by the way). The most infuriating thing is that even when I leave the Mac downloading something, the connection drops as soon as the display turns off. The same thing happens with a torrent client in full activity. Every now and then, the MacBook Pro seems to struggle to reconnect to the Wi-Fi network it was connected seconds before. More frequently, the MacBook Pro appears to be connected to the home network — the Wi-Fi icon in the menubar displays maximum signal and all that — but there’s no actual flow of network traffic. I try to load a website, and the connection times out. Sometimes turning Wi-Fi off and on fixes this. Other times, out of curiosity, I just let the Mac sit idle for a while, and the connection just resumed by itself without intervention. Oh, and connection speeds are volatile, whether I’m downloading a file or simply browsing the Web and checking email.

As far as I know, there’s nothing wrong in the MacBook Pro’s hardware. It’s as if the Mac — Mac OS X update after update — has become less capable of handling stable Wi-Fi connections when it’s far from the transmitter, or when it doesn’t receive a ‘pure’ 802.11n wireless connection. 

You may say: “Maybe the MacBook Pro is in a particularly bad spot of the apartment, where Wi-Fi reception is compromised.” Maybe, but: 

• It’s in the same spot as it was four years ago, when it was running Snow Leopard, and everything was fine then;
• The Power Mac G4 Cube that’s on the same desk as the MacBook Pro has no problem whatsoever in maintaining a Wi-Fi connection (it runs Mac OS X 10.4 Tiger);
• One day I placed the 17-inch PowerBook G4 in the very same spot of the MacBook Pro and it connected — and stayed connected — to the Wi-Fi network flawlessly.

So I don’t think it’s a problem related to the position of the computer or to any possible increase in Wi-Fi interference, because if these were the cases, all the Macs in my studio or not in the vicinity of the router would have developed Wi-Fi connection issues. If anything, after getting rid of the microwave oven, there should be less wireless interference.

Now what?

I’ve researched the Web extensively over time in search of any kind of solution to mitigate the issue, and I’ve tried all the tricks I could find on forums and discussions and blog posts, but nothing has changed. At the moment I’ve resorted to connecting the MacBook Pro via Ethernet cable to the AirPort Express base station in the hallway outside my studio, but it’s not the most elegant solution and the cable is constantly in the way.

Unfortunately I don’t have the time or the technical skills to investigate the problem inside Mac OS X. In other words, I can’t offer hard proof that recent versions of OS X are at fault here. All I have are these empirical observations, which can be summed up as follows: in an environment that has remained the same over the years (same placement of Wi-Fi devices and wireless clients), the Wi-Fi performance has got worse on the only ‘modern’ Mac receiving Mac OS X upgrades. Other PowerPC Macs that can’t be upgraded past Mac OS X 10.5 Leopard are not affected, and display a strong, consistent Wi-Fi performance, never dropping a connection no matter where I place them around the apartment. 

When OS X Yosemite was introduced, I was tempted to upgrade right away to see whether it could reverse this terrible trend related to Wi-Fi performance. But reading articles such as this one at Macworld, and hearing from a few friends who have experienced severe battery life losses right after upgrading to Yosemite, has made me reconsider, and I’ll probably wait for version 10.10.1 before making the jump.