If I had to guess, I would put my money on Apple shoehorning Thunderbolt into the next generation of MacBook Air.  However, I can see several reasons based on what is out there now which indicate that it will not make the cut.  So, quite ironically, while I think Thunderbolt will make it into the next MacBook Air, I’m going to outline why it won’t.

Physical Space

The MacBook Air is some pretty serious engineering.  To hammer a fully capable laptop computer into the Lilliputian internal space found inside the MacBook Air’s brief unibody enclosure is no small feat.  Not to mention most of the internal space isn’t even computer – it’s slices of lithium polymer battery.  Viewing images from a site like iFixIt, showing complete tear down of the 11 and 13 inch MacBook Airs, it’s plain to see that it’s quite densely packed in there as it is.

At this time, Thunderbolt comes in the form of an additional chip of not insignificant size to add the wondrous capabilities that it does to the questionable MiniDisplayPort.  To shoehorn yet another chip onto the logic board of the incredibly densely packed Air is… well it’s something.  It’s a task meant for men greater than I.

A fantastic option and future inevitability is for it to be integrated into the system controller, in whatever form that may come in the next Air (odds are an Intel chipset).  And being an Intel chipset (probably) only adds to the hopes that it would be, however, it has not been as of yet.

Is it impossible to get the thumb sized chip in there?  Certainly not.  But it sure seems difficult.

Also.  This same reasoning is why we could have seen/could see a MiniDisplayPort/Thunderbolt iPad but almost assuredly not an iPhone.

*Warning: This kind of drifts off toward the end.

A friend of mine is hanging onto his PowerBook G4 12” for dear life.  It’s admirable.  He’s not an idiot with his money, I don’t think, and he is happy to work with what he has, so he’s not jumping at every new model that comes out.  I think he’s a little nuts for not having upgraded even once but one thing that’s important to this PowerPC stalwart is the form factor.

Up until recently, nothing has rivaled the PowerBook G4 12” for foot print, at least not in the Mac world.  The 13” MacBook Air certainly beats it in portability, but footprint is also important to the guy I guess.

Despite the claims and tests and results indicating that any Intel Mac will annihilate any PPC based Mac in almost any given benchmark (anyone ever read that Mac Mini Core Duo vs. a contemporary XServe G5?  Knocked it out of the park in everything but disk access, probably due to the laptop style hard drive of the Mini) he was not prepared to believe that anecdotally, in actual daily use, that the speed makes a difference to a basic user like him.

And I can’t argue with him on it because when you have a person that’s satisfied with what they’ve got, they need not be fought.  Why dig in and attempt to knock someone out of their comfortable perch?  You don’t do it.

However, the only reason for going ahead with the kind of enthusiast research that I did is either personal interest, which was certainly present, or the fact that he is looking forward to the next Mac, and wants the most powerful, most portable Mac he can get.  So part of his game is awaiting the next great thing and hoping it meets his stringent criteria.  If he’s going to take the plunge, he wants as much as he can get.

He regaled me with tales of Mac fanboy message boards with, among other things, people taking PPC to their graves, people defending the aged Penryn Core 2 Duos against their (obviously) superior Sandy Bridge up and comers.  They insist the 320m video/system controller is not only more powerful but simply must be FAR superior to even the latest Intel HD integrated graphics.  Sufficed to say, I don’t put a lot of stock into any of Intel’s integrated graphics but I do observe benchmarks and must take into consideration its features and the realistic uses of the machines it’s found in.  I’m not going into the features or capabilities of the Intel HD Graphics at this time though.

This is a rough examination of what is theoretically possible in the MacBook Air.

The original bodied MacBook Airs, the tapered models, employed Intel Core 2 Duo cpus of the Penryn generation running at clock speeds of 1.6 or 1.8 GHz with a 2.13 GHz option coming along near the end of the life of that particular style of Air.  Most critical to this examination are the thermal characteristics of the CPUs, which somehow, by magic I think, came down as the processor matured, and matured, and matured.  The initial Penryns, in the customized MacBook Air package, ran at 1.6 or 1.8 GHz with a Thermal Design Point of 25 watts, meaning it was engineered to dissipate that much heat energy or less.  The second generation ran at the same clock speeds but on a revision of the core’s architecture which dragged the TDP down to a scant 17 watts, resulting in a cooler, longer running Air.  As far as CPUs go, this is very, very low.  Desktops range from 35 watt TDPs up to 195 watts and beyond, and even the range of 65 watts is considered a major selling point and a nice, cool, desirable place to be, where energy and heat are concerned in a computer’s CPU.

Later, we arrived at the redesigned Air, the wedge design, which ran at suspiciously similar clock speeds but, again by some kind of magic, better performance – very possibly due to its coupling with the custom nVidia 320m system controller.  The 13” wedge models ran again at the same 1.86 and 2.13 GHz speeds as their predecessors with the same impressive 17 watt TDP.  The new 11” wedge models utilized newly minted Penryns at 1.4 and 1.6 GHz speeds with mind boggling 10 watt TDPs.  The latest, well matured Penryns coupled with their nVidia 320m system controllers created machines that seem to perform well beyond their stated clock speeds.

They’re not Sandy Bridge though.

I refer back to benchmarks, as I do admittedly have almost no actual experience to fall back on.  I ADMIT IT.  But the benchmarks are so resounding that it’s very safe to assume that we’re facing more than a few milliseconds shaved off of any given operation (more like entire seconds, or entire minutes!)

I looked up the lowest TDP components in the Sandy Bridge range (note we’ve entirely skipped Arrandale) and found promising contenders.  One i5 CPU and two i7 CPUs roll in at the 17 watt TDP.

The i5-2537m, possessing 2 cores and processing 4 threads assisted by 3 MB L3 cache at speeds ranging from the stock 1.4 GHz to a Turbo frequency of 2.3 GHz!  (Conditions allowing).  The i7-2617m and 2657m both also have 2 cores processing up to 4 threads assisted by 4 MB of L3 cache at 1.5 GHz(turbo up to 2.6 GHz) and 1.6 GHz (turbo up to 2.7 GHz) respectively.  All three of these wondrous CPUs meet the 17 watt TDP apparently required to fit into the requirements of a MacBook Air.

Now, this was what was most important to my decently educated mind.  But there’s another largely unknown ingredient which is the power necessities of the Intel System Controllers versus the standards of other controllers such as the 320m.  Unfortunately, I am unable at this time to locate TDP or power specifications for the older 9400m based controller or the less old 320m based controller, but potential chipsets which would be coupled with the Sandy Bridge cpus have minimal thermal requirements in the range of a mere 3.4 watts.  This simply must be less than a system controller with a built in video subsystem.