Solipsism Gradient

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Re: More tradeoffs

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Having looked at the new MacBooks it’s time to examine the new MacBook Pros.To recap, my main point is that the MacBooks have been designed from the 13.3″ form factor inwards, and that the MacBook Pro, having a 15″ display and more internal space, is really an expanded MacBook.

(The contrast is, of course, to the usual view of the Pro version as being the “real” machine, and the consumer version as a maliciously crippled of that.)

Looking at the internal space is, again, instructive. Refer to step 9 on the ifixit site. Now compare this to step 11 for the MacBook. Notice that the depth of the battery/drive compartment is the same (the hard drive being a standard 2.5″ model), so the Pro’s battery is only a little over an inch wider than the MacBook’s.

The optical drive is in the same position and is the same size. To its right from this angle, the motherboard is an inch wider and deeper than the MacBook’s it also has another cutout for a second fan, necessary no doubt because of the Pro’s extra power requirements. These, in turn, are a consequence of the larger display, added video processor, higher CPU speeds, and the extra drivers for the ExpressCard slot and the Firewire interface. Of course, all that needs a larger battery, as we’ve seen, and a beefed-up power supply/charging circuitry.

Look at the motherboard in step 20. The ports are the same, except for the inserted FW800 connector.The empty space to the lower left corresponds to the ExpressCard slot, which is actually below the board (check it out in step 24). As in the MacBook, there’s no wasted space, and changing anything will involve some tradeoff where something else would have to be removed.

To recap, the added space made possible the added features. When the updated MacBook Pro 17″ comes out, it will have even more space, and I can only speculate what this space will contain. As before, the larger display will need more power, so we’ll have a wider battery – maybe 1.5″ wider than this one. If they maintain the same depth, there’ll be some empty space – good for conserving weight. On the other hand, they could sacrifice this space, either to get longer battery life, or to feed more circuitry – quadcore, anyone? And/or 8-16GB RAM?

By the same token, there’d be leeway to have either a second FW800 connector, or eSATA; perhaps both and/or a third USB port. I don’t think that an SD slot (or other media slot) is in the cards, as Apple probably doesn’t want to get locked-in to a particular format, and USB adapters are so cheap. I can’t see Apple using any of the extra space for a full-size DisplayPort as they seem to be trying to pull the industry into using the mini size for that everywhere.

In a few weeks we’ll see how the new MacBook Air looks inside; I suspect we’ll see fewer screws and a similar motherboard layout.

Re: More tradeoffs

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A correction regarding Apple’s mini-DisplayPort connector. The DisplayPort organization’s page is none too clear, and the actual standards aren’t available for free, but it now appears that Apple has been instrumental in working with them to define the new mini connector; unlike past “minis” adopted by Apple, this seems to be a bona-fide standard. So there’s real hope of it being more widely adopted by other manufacturers.

I don’t see any major advantage in the full-size DisplayPort connector, except perhaps for the optional locking mechanism on the plug. Don’t expect it to appear in any Apple products; in any event, mini-to-full cables will probably be sold by third parties.

There’s an interesting picture on the interoperability page: it shows what appears to be a previous-generation MacBook, with USB, FW400, FW800, S-VHS and the full-size DisplayPort connector. Looks like a Photoshop job to me… icon_smile.gif

On the Air

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It’s now almost a week since I’ve ordered a MacBook Air, and it arrived two days later. As usual, the packaging is superb and everything worked out of the box. I spent a couple of days upgrading and installing software, getting a faster WiFi network up at home, and generally testing things. I was unable to get a USB-Ethernet adapter though; neither Apple’s nor third-party models can be found in local stores so far.

The Air is everything I expected; excellent design, very light, runs somewhat hot under heavy CPU loads, takes longer than it should when recharging – I measured 4 hours to recharge from empty to full with the machine sleeping.

What I didn’t quite expect, with all the whining about it being slow, was the speed. Building Quay on it is at least twice as fast as on my not-quite-2-years-old iMac G5 (2GHz, single CPU). I suppose that hard drive-dependent operations will prove slower, but then it’s a puny 1.8″ drive.

All in all, I’m planning to use the Air as my main development machine away from home, and it should be fully set up in time for our upcoming Europe trip in May.

Two interesting developments came up while I’m studying for my next post about code signing.

Firstly, every developer who has signed up for the $99/year program has gotten a letter which says, in part:

We have received your enrollment request. At this time, the iPhone Developer Program is available to a limited number of developers and we plan to expand during the beta period. We will contact you again regarding your enrollment status at the appropriate time.

The message for non-US developers also mentions that the program will be implemented in the US first. At this point, some developers went off in a huff, interpreting it as a rejection, and numerous complaints and conspiracy theories have been aired. So far (as I know) nobody who applied to the $99 program has been formally accepted – the ones who said they were are apparently newbies interpreting their ability to download the SDK as “acceptance”. On the other hand, a handful of companies have stated they’ve been accepted into the $299 enterprise program.

Well, my understanding of English may be faulty (it’s only my fourth language, after all) but let’s look at the 3 sentences I quoted above:

We have received your enrollment request.

Nice of them to reply.

At this time, the iPhone Developer Program is available to a limited number of developers and we plan to expand during the beta period.

This is just repeating what Steve Jobs said during the iPhone event… nobody would expect Apple to accept all applicants immediately and at the same time. There certainly are several thousands at the very least.

We will contact you again regarding your enrollment status at the appropriate time.

Meaning, as soon as we dig out from under, we’ll check your application. I see no problem there either.

Apparently, some people are indeed interpreting this as a poorly worded rejection, or at best as an ambiguous directive that you have to go to the end of the line or try again. Now, I’m the type of person who has difficulty in understanding the logic of “I’m afraid I’ll have to tell you that your credit card has been declined” – the first time I heard that in person I couldn’t follow at all (heh! he’s afraid of what? will he have to say what in some unspecified future? Why doesn’t he then say whatever he will have to say, then?) But I can’t see anything like that buried in that last line either.

Second item is that the SDK’s restriction on background process has been much-commented on, among others by John Gruber and Mike Ash. Along the way, there have been complaints about this and other restrictions imposed on third-party applications. Some have even pointed out (I can’t confirm or deny) that the APIs published in the SDK are just a small subset of the APIs ferreted out by people examining the previous iPhone firmware. Some commenters even seem to believe that Apple not publishing certain APIs is illegal in some way… witness the comments about unpublished APIs called by WebKit/Safari some weeks ago.

Well, Apple can certainly opt to tell people not to use certain APIs. In fact, on the Mac in the past, some large software publishers went ahead and used some of those “hidden” APIs anyway, with the result that Mac OS X still has to support lots of legacy calls that are broken, but can’t even be properly fixed without breaking those applications!

So, on the iPhone, they’re certainly making sure to avoid the legacy/unsupported/hidden API problem at all costs. Apparently the SDK license says that applications may not use any unpublished API, period. Note that this does NOT mean that Apple will have to examine your precious source code line-by-line; no, they’ll just run a tool that looks at your executable, sees what symbols in which frameworks are referenced, and produce a listing of whatever non-documented stuff you’re calling.

So, there are no documented APIs that let you run an application in the background, or start a background process. I’m sure we all agree that having any GUI application continue in the background after another GUI application starts will be too resource-hogging – after all, if you allow one, you have to allow any. From what I’ve read, no Apple application does that either; a few seem to have a background process or daemon running to take care of communications, but that’s of course much more lightweight.

I agree with Mike that obviously the iPhone OS does support multitasking in a generic way. I also agree that the relatively limited RAM (I heard that 64M are available to a third-party application) and CPU speed are no obstacles. To mention an even older example than he gives, I managed to write an embedded system running on a 4MHz Z80A CPU, with 32K of RAM, that handled a GUI, a foreground thread, and two background threads tracing several realtime signals on a screen.

But make no mistake, embedded systems are hard to keep responsive, even if you have no arbitrary code running at all. Apple apparently elected not to have full virtual memory swapping in the iPhone OS; here again, it’s not a limitation of the hardware (Flash memory can support swapping) or of the OS (it’s Unix-based after all) or of the CPU (it does have page tables etc.).

No, I think Apple simply is trying to keep “teh snappy” always happening, keep battery duration as high as possible, and avoid Flash RAM filling up by swapping. Also, swapping pages takes time and burns battery power. A wait of 2 or 3 seconds may be shrugged off if you sit at a desktop computer but may be unacceptable if you’re trying to answer a call on the iPhone.

Consider the MacBook Air with SSD. It has 64GB of flash and 2GB of RAM, with full swapping virtual memory of course. I’ve seen people leaving 20 or 30 applications running on a Mac and not noticing that their swap files grew to 12 or 20GB… but even that may already become a problem on the Air. I suppose Apple didn’t want to face telling people that they should leave 2 or 3GB free on their 8GB iPhone… and risk crashing or hanging when it suddenly fills up.

Still, I feel that if you do have a compelling application that absolutely depends on having a background process running, you’ll probably be able to ask Apple for an exemption… if you can prove that your process won’t hog the system. Also, Leopard (for one) has facilities to start processes on-demand – using launchd, you can have the system watch a certain port or socket and start up your process when data arrives there. No doubt we’ll see more such facilities being deployed.

Re: Design snowball

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uliwitness wrote:

Oh, BTW, also found your review of the FireWire power specs interesting. I was hoping someone with better electrical skills than me would eventually post the fundamental maths involved to prove/disprove the “No FireWire cuz it needs too much juice” theory that’s been bandied about.

The post was already too long, so I didn’t mention the possibility of using the Sony 4-pin FireWire connector, which doesn’t supply any power; it’s also much smaller, getting around some of the space argument too.

Still, it’d be a hassle needing an external power supply for those small portable FW drives; most of them don’t come with one. Also I’m not sure whether Apple would have to pay Sony for that.

As I also said previously, each extra USB connector would also need more space and power, though less (2.5W) than FireWire.

Re: Design snowball

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Posted by uliwitness:

“When it comes to Japanese PC manufacturers, their manufacturing plants will complain or add their own technical efforts to lower cost, if a proposed structural design was insufficient,” one of the engineers said. “The MacBook Air gives me an impression that its manufacturing plant packaged the computer exactly as ordered by Apple.”


thanks for posting this — it mirrors exactly the thoughts I had when I read this news bit, and now I don’t have to coherently blog about it anymore.

FWIW, from what I heard, this is a common thing with Asian manufacturers. They like to improve products, but since they usually don’t have the whole list of why something should be done this way and not another, the customer of these manufacturing plants isn’t always happy with that.

Some western companies have “solved” this by putting QA guys in place that will babysit the manufacturers and make sure stuff gets produced the way they requested it, for exactly that reason.

I guess this is a cultural issue that will have to be resolved by understanding each other…

Oh, BTW, also found your review of the FireWire power specs interesting. I was hoping someone with better electrical skills than me would eventually post the fundamental maths involved to prove/disprove the “No FireWire cuz it needs too much juice” theory that’s been bandied about.

Re: Design snowball

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The snowball effect I was writing about is also very evident in the design of the MacBook Air. I’ve posted before about some aspects of this (I was wrong about it having fewer internal screws, though).

Just saw this: Japanese engineers trash MacBook Air. Here’s the original article in somewhat clumsy English. Some choice quotes:

“Can we say that the MacBook Air has a perfect, sophisticated external appearance, but its insides are full of waste?”

What astonished all those engineers was the fact that the computer had a very costly structure. For example, it used an extremely large number of screws to attach components. About 30 screws were used to attach the keyboard alone.

“When it comes to Japanese PC manufacturers, their manufacturing plants will complain or add their own technical efforts to lower cost, if a proposed structural design was insufficient,” one of the engineers said. “The MacBook Air gives me an impression that its manufacturing plant packaged the computer exactly as ordered by Apple.”

Based on the results of our teardown project, we guess Apple is not paying much attention to both workmanship of the hardware design and comprehensive cost reduction…The MacBook Air’s mysterious internal design might be a violent antithesis against Japanese manufacturing, which allows no compromise even in detailed parts of the hardware.

This is a very interesting insight into manufacturing. Can you imagine Steve Jobs’ reaction to somebody at the Air factory deciding to take out 25 of the 30 screws that hold the keyboard? Heads would roll!

No doubt all those screws (and the other things they considered “waste”) contribute to the Air’s extremely solid feel that’s remarked upon by everybody who has handled one. Contrast this to all the “this thing must be soo fragile” comments, just after the launch, by people who had not handled one. Obviously people are used to small electronic devices following the (apparent) Japanese practice of shaving off internal “waste” to save a little space and money and ignore the consequence of a flimsy feel… something that would be especially accentuated in such a thin device as the Air.

So, this article betrays a fundamental misunderstanding of Apple’s design strengths and intentions. Their definition of “workmanship and… cost reduction” is very different. From what I can tell, the Air was designed from the outset to be extremely thin and rugged, while maintaining adequate battery life and performance. These considerations snowball to the extent that the battery uses up 2/3 of the space, and seems to be (along with the keyboard) itself a structural element.

Everything else flows logically from that. To put in a FireWire connector means reserving resources for a 7W additional power drain – that’s 1A extra current at the 7.2V battery. It also means an extra power supply to jack this up to the 9 to 12V required at the connector, extra PCB traces, and so forth. The battery has a capacity of 37 watt-hours, meaning that at the rated duration of 5 hours, the average power draw is slightly over 7W; this would double when a FireWire drive is connected, meaning battery life would be only half, 2.5 hours. Also, the extra connector would mean widening the flip-down door and shaving off maybe 2cm off the battery on that side… more capacity reduction. The 45W external power supply would also have to be beefed up, and the internal charging circuitry as well… this means more heat dissipation. It would probably have been necessary to make the battery itself thicker, maybe 5mm or more.

Now look at a typical Ethernet connector; it’s thicker than the Air’s door, so some millimeters would have had to be added to the Air’s thickness, too; as well as taking the extra chunk out of the battery as well.

Same applies to an internal DVD drive. If it doesn’t work as a burner too, they’d have complained – but imagine the power requirements, or read the Lenovo x300 review; Lenovo engineers are very capable too, but they decided on different trade-offs. I have handled some other brands of small laptops from Toshiba and I must say I was unimpressed by the feel and finish.

Finally, imagine the Air with a removable battery. This means extra connectors, a case opening, of course with either a full-width extra wall (meaning at least 4mm extra thickness) or some heavy-duty latches (considering the battery is 2/3 of the size and a similar proportion of the weight of the Air). Consider the loss of rigidity that would imply, and the extra size and weight that would have to be “wasted” to counteract that.

So that’s my point. Any change in the Air’s design immediately snowballs into a larger, heavier, hotter and (probably) less solid-feeling machine. Jobs obviously thought it was worthwhile to concentrate on those aspects, and it’s rather shortsighted to conclude that “Apple is not paying much attention to … workmanship”.

Some more thoughts about the Air.

I finally saw the pertinent parts of the keynote and paid attention to the shots of the Air’s interior and of the main board. Wow, that thing is cramped; 2/3 of it is battery. There’ve been serious announcements of progress in battery technology and for the next years we can expect even slimmer machines and/or longer capacity; still, it seems that Apple now considers 5 hours (if real) as a good compromise between bulk/weight and battery life.

The Air no doubt makes use of Apple’s recent patent (sorry, no time to find a URL for it) for glueing together a precision-cast aluminum chassis – meaning very few internal mounting screws and posts, much tighter tolerances, and serious amounts of weight and dimensions shaved off, as well as better heat distribution. It also means that the case feels like a single unit; it’s significant that people who’ve handled the Air report that it feels very solid, not at all fragile like it looks. Especially the moveable port door is said to feel solidly reliable.

People calling for a removable battery no doubt are unaware that such a thing would mean a huge case opening, meaning extra ribbing elsewhere to counteract the rigidity loss, mounting screws and a good lock, what amounts to a double wall inside the unit when the battery is mounted, a pair of connectors and so forth. Meaning perhaps 200g extra in weight, 4mm in depth and $50 (at least) added to the bill of materials… all to accomodate maybe 10% of users who need an extra battery for flying tourist class?

I remember from my hardware design days how there are cascading design choices like this. Someone comes in and says “can’t we do such-and-such” and they fall off their chair when you explain the consequences. Another example is the much-bemoaned lack of peripheral ports. But consider FireWire. Yes, Apple pioneered FireWire and it’s a great technology… but check the power requirements:

…[it] can supply up to 45 watts of power per port at up to 30 volts…

That would be the entire 45W of the external power supply right there! Admittedly Apple’s other laptops already lower that to about half by supplying less voltage. For instance, the FireWire developer note says for MacBooks:

The MacBook’s six-pin FireWire connector provides unregulated 9 V to 12 V power with a maximum load of 0.75 A. Developers should design to use 7 W sustained power, or less.

Contrast this to the new MacPro, which can supply 18W per port (28W total on all four ports), and you see how laptop power design considerations are important. Supplying 0.75A to get the standard 7W on a FireWire connector would have meant larger board traces, probably a thicker board, an extra power supply chip for the higher voltage, extra dissipation, cooling… not worth it. Lowering that requirement to 5W or less would mean many external drives not working properly.

The same reasoning applies to USB. A standard USB port must supply 0.5A continuously at 5V – 2.5W. The new MacPro and the latest revisions of the laptops (including the Air) support a special high-power mode where one port can supply 1.1A (5.5W). This was meant originally to allow the keyboard to work as a powered hub, supplying the regular 0.5A on each of its ports. The Air probably needs it for its external DVD drive, although the USB Developer Note says this only works for the keyboard – and supposedly the Air’s external drive doesn’t work on other Macs. Time will tell, but here too an extra USB port would have meant beefing up the machine, though not as much as a FireWire port would have.

Somewhat more puzzling is the limitation of the 80GB 1.8″ drive, as there are larger drives sold in iPods. Either Apple is already supply-constrained for those, or the slight differences in thickness and power consumption are significant; in any event, I expect the Air’s next revision to offer larger drives. Same for RAM; coming back to the pictures of the main board, notice there’s no space for extra RAM chips, meaning that 4GB will only be possible when the next chip series doubles capacity. (And a RAM socket? With a door? Forget it.)

Finally, all this is a great opportunity for acessory makers; expect a 4-port USB hub (powered, of course) with built-in gigabit Ethernet and media slots, for instance. Even for Apple itself, it might be interesting if Time Capsule allowed a plug-in DVD drive for remote access; it would just mean a firmware update, but I suppose the Air’s drive would be too much for the Capsule’s power supply.

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