Bill, a recent convert to Apple (I take naught less than the fullest of credit) came up with the following questions via email, and only this morning:
“Boomer, yo you know if upgrading a 802.11g wireless network to 802.11n would affect the battery life of connected wireless clients? I am hoping that perhaps such an upgrade would reduce power usage by the clients. Specifically, I have a wireless network consisting of two older generation Airport Express (802.11g) units, that Melissa gave me, set up as a wireless distribution system. My 13″ MacBook Pro is wonderful, but the battery life is less than I’d hoped. I’ve wondered if purchasing an Airport Extreme base station and switching to 802.11n would help.”
I am widely referred to as a “Cultural Architect”.
I like that title and work efficiently, and daily, to earn it.
Don’t confuse me with most engineers. However, I am capable of solid research, and I can sort out many technology challenges instinctively.
A common issue right now in the land of Apples is significant drain on PowerBook (laptops) batteries when Apple’s renowned Airport technology is running. The focus is on the difference between 802.11g and 802.11n.
I have never done a rigorous comparison, but my gut says it won’t. My home has both an 802.11n network (5 GHz, not 2.4) and 802.11g. I’ve used my MacBook Air and several MacBook Pros for extended time on each of them. I have never noticed a difference in battery life when operating on one or the other.
There may be a difference, but based on my experience, if there is, it’s so slight as to be virtually unnoticeable.
Nonetheless, here are my extended thoughts around this oft-lamented concern:
NOTE: I’d expect the difference between 802.11n and 802.11g to be minimal, at best. However, my point is relevant in terms of our combined and passionate pursuit of perfection and Apples illustrious role in that great effort.
I learned something not many others know over the weekend. It does not have to be fascinating, only vitally relevant… When active, 802.11n apparently uses more power – but what really matters is energy, not power (Example: If you can use one (1) Watt and get the job done in one (1) second, then sleep at zero (0) Watts for the next two (2) seconds, you use less energy than something that uses zero point five (0.5) Watts, and takes three (3) seconds to do the same job that consumes one point five (1.5) Joules instead of just one (1)).
So… It occurs to me that a better question to ask is: “how do I extend my battery life?”
There are many things you can do… Probably one of the best is to reduce the display brightness. I won’t do that because I like my screen bright and cheerful. This means I won’t typically run my laptop at the lowest possible brightness when on battery, but you might not find that comfortable to work with. So dim it! Do it now!
A second major consumer of power is the Central Processing Unit (“CPU”). Make sure the Energy Saver control panel is set for better battery life. I prefer “optimal performance”. But, this tip is for most everyone else. Also, keep in mind that applications using the CPU will use power as well. Some applications behave well when not doing anything and don’t use much CPU, but others (Example: EyeTV and Microsoft Office come to mind. so this is an opportunity to rally true Apple loyalists and remind them NOT TO USE Microsoft products. native Apple applications like Mail and iCal are terrific) are poorly-behaved and waste CPU cycles even when they’re doing “nothing”. This is also a reminder that you can use the Activity Monitor application in /Applications/Utilities to see how much power CPU applications are using. Also, turn off (or unplug) anything you don’t need – bluetooth, CDs/DVDs, Airport, USB devices, etc.
So, there you have it. And, possibly, with a flourish – certainly a bow.
Bill, you can address this post (because I know you read the Blog) and comment once you’ve sorted out the genius of it all. Also. let me know if Melissa gets you that 27″ iMac for Christmas (although you are, indeed, my Jewish brother – even though I’m not always Jewish) as I’ve advised her you are well worth it.
Peace be to my Brothers and Sisters.
Brian Patrick Cork