power efficiency

[jarod-ajLrJawYSntWk0Htik3J/w at public.gmane.org (Jarod Wilson)]

On Nov 24, 2009, at 5:52 PM, Chris O'Connell wrote:

> That's a good question.  My Macbook gets SUPER hot, so hot it's almost unbelievable.

My MacBook Pro doesn't get very hot. Ever. But most of the time, the heavy computational stuff is being done on either my core 2 quad myth backend or my dual quad-core opteron web/mail/file/build server in the basement. And for video playback, h.264 1080p stuff played back in QuickTime uses marginally more than 0% cpu, as Apple has the equivalent of VDPAU for the nVidia graphics chipsets[*] in this thing.

> That being said, the battery life is really good.  I think Apples in general have really good batteries.  The newer generations especially.  Some of the newest Macbook Pros can last 7-8 hours due to the new super high capacity battery.  The new batteries have a 1000 charge cycle compared to the 300 charge cycle of the older machines.

That would be the one I have. All the hokum over "zomg, the battery isn't hot-swappable" is a joke too. Its 8 screws on the bottom of the case to pull it out and replace it if you need to. One of the first things I did was disassemble this thing, pull the 500G rotational storage in it, and put in an Intel X25-M solid state disk -- which also helps out with the battery life and keeps the heat down.

> I don't think there is anything inherent in the OS X operating system that contributes greatly to the battery life being extended.

You're incredibly wrong. Mostly "what Richard said".

> The power management options are similar to that of Windows or Linux.  Perhaps there is something going on behind the scenes to in the OS to extend the battery life.

Linux power management is getting better all the time, but quite frankly, it still sucks pretty hard compared to both Windows and Mac OS X. Mac OS X especially. More of "what Richard said". Apple has a lot more control over what hardware their OS is running on (at least in a supported fashion) so they don't have any cheap crap hardware like what ends up in your budget Windows-targeted laptop or netbook, and the drivers for pretty much everything are frequently better tuned (by Apple themselves) for power savings than Linux drivers even for the same quality hardware, which often are simply functional under Linux, with things like auto-suspend and auto-resume of pci express root bridges being an afterthought (or too difficult to reverse-engineer). Similar with graphics chips and any number o
 f other devices in the system. I can go on and on, but the basic thing is that Apple has superior driver support for the smaller set of devices they support, particularly when it comes to eeking out as much power savings as possible. And every little bit helps.

> On Tue, Nov 24, 2009 at 5:43 PM, Tom Metro <tmetro-blu-5a1Jt6qxUNc at public.gmane.org> wrote:
> Jarod Wilson wrote:
> > The battery life on my 17" MacBook Pro under Mac OS X slaughters the
> > battery life on any Linux-running netbook too.
> 
> Really? Is that attributable to the power management in OS X being that
> far ahead of Linux, or is it the MacBook Pro hardware?

Both.

And we haven't even touched on how well other features like auto-dimming the screen in low-light situation, lighting up the keyboard backlight, etc. all work. Not to mention how slick the 24" Apple LED display is with its built-in power adapter for the laptop and the way hot-plugging it actually WORKS the Right Way, 100% of the time upon simply connecting the monitor while Linux still requires manually re-probing for attached displays, and even then, still doesn't always work properly...

Believe it or not, yes, I do still work at Red Hat. :)

[*] Yes, chipsets, plural. I have it set to use the lower-power 9400M when on battery and the higher-power 9600M GT when hooked up to power.

-- 
Jarod Wilson
jarod-ajLrJawYSntWk0Htik3J/w at public.gmane.org