…how tightly coupled should it be?
i can’t help to think about it. i’m writing this post on construction that was defended to his last days by Steve Jobs. according to his belief, only software tightly integrated with software can be effective and predictable. independently of what Steve believed, there are other examples of such thinking in the world.
let’s take for an example company i work for - Cisco. most of our solutions are based on software integrated with hardware without ability to add questionable “apps” to the mix. only then vendor can claim predictability, and so it happens across the whole market of network devices (and not only them).
why was i thinking about it? i was fighting a problem with upgrading my MacOS X from Lion 10.7.4 to Mountain Lion - 10.8.0. unfortunately, after upgrade my effective battery time went down from 7-8 hours on my 17" MacBook Pro, to barely 4-5 hours. many people point to Power Nap as causing troubles, as it was identified to cause problems as early as in november 2011. SMC firmware update seems to have caused all kind of side effects and while Power Nap is unavailable on my MacBook Pro - it still negatively impacts the operation.
after moving to 10.8.2 and calibrating battery once again, i’m getting 6 hours+. why only so? another suprise - i upgraded my MacBook Pro to 16GB of RAM (from initial 4) and then put two Intel SSD 710 in RAID0 inside. i wasn’t thinking about that before, but now looking at specs i get the point - one of those Intels can use up to 3.7W of power during read/write cycle, and 0.7W in standby. it’s a lot, as original 750GB HDD was using up to 2.4W.
i’m switching then to WD WD10JPVT, which according to specs takes only up to 1.4W during peak usage, and 0.59W in standby. one 300GB Intel SSD drive and one WD as storage may be better idea for mobile workstation than two power-hungry Intels.
and as a side note - given i dig down into MacOS X internals, i can highly recommend this book - MacOS X internals.