Remember when you wrote these words?
http://uk.youtube.com/watch?v=4GPcUSnKdK4
(1 min 36)
The same process was used on the Macbook Air.
So forgive me if I don't regard you as the world's
number one expert on build quality
It's rolled sheet. Not cold-forged block. The manufacturing process uses aluminium which is formed under low temperatures (i.e. not at melting temperatures of the alloy) into basically thick sheets, and not from a discrete block forged to be machined. The former is easier to machine, but weaker. Aluminium which is made any other way (block or sheet) will be too weak for this type of use, but you can easily test the difference between rolled and forged pieces by hitting it with say steel. The rolled (As on all recent aluminium-crafted Macs) piece will pit relatively easily: The forged will not. It is perfectly possible to mass-produce things from such blocks - but the cost will be higher - and a unibody Mac made that way may end up even heavier.
Actually, now that you mention it there's an interesting lesson to be learned from all this.
For example, Dell uses magnesium shells in their XPS M1330's which contain more recent engineering / materials innovation than the relatively low-tech (in terms of the materials working processes involved) Apple approach. The shell + internal chassis is almost as rigid in overall structural terms as a unibody construction, but considerably lighter and thinner. And there's good reasons why both companies do the things the way they do.
The Dell approach is a more efficient method of manufacture for low-margin mass production, and allows you to pack more in to the notebook to hit the same weight. When Jobs worked on the NEXT, the casing was constructed of magnesium alloy - because it embraced newer techniques in construction of enclosures at the time, and it was also aimed at people who understood what magnesium was. And until the current generation (as do/did many other notebooks), the portables used magnesium inner frames, which was one of the lightest, most efficient way of having an endoskeleton in a notebook computer at reasonable manufacturing cost.
But the Apple approach is designer / marketing-led. I would bet that Apple rejected outright the use of magnesium as an external casing purely for one reason: It doesn't feel like metal. The unibody approach results in possibly the heaviest construction method for a load-bearing shell given what's available at the moment - and this is of course one of the reasons they dropped the battery capacities to hit the target weights, the batteries being among the heaviest parts of a laptop. But it definitely feels like metal.
The tactile experience is premium to the uninformed, even if everything else which underlies it is not.
When you're dealing with the technologically illiterate crowd that Apple primarily embraces, it's a given that people won't be able to tell the the difference between magnesium or plastic - and telling them it's made of magnesium, since there's no significant tactile or visually discernible enhancement, is a bad move on the part of a manufacturer concerned about such matters. A percentage of Dell M1330 owners who are potential Switchers - i.e. the aforementioned technology illiterates - probably think the casing
is plastic. And examining it in terms of perception, it becomes a marketing issue.
By hyping up possibly the oldest / the least efficient way of making a lightweight casing suitable for mass production, Apple once again highlights the effectiveness of marketing and knowing your clientèle inside out, as well as having a CEO who knows the absolute importance of this - when you're peddling bull**** to the dumb masses. The likes of Dell, by having a less competent marketing department, lacks the ability for those parties to dictate manufacturing terms in the same manner. Many of the differences in the ultimate engineered-in suitability for the intended purpose of the machines come from this difference.
Sony have access to superior manufacturing methods, but a similar level of understanding of how their clientèle would perceive materials: This is why they call their premium laptops carbon fiber, instead of short-fibre reinforced thermoplastic. The thermoplastics used in Sony's cases are a very good solution to making computer cases - it's more durable than many other materials when used in a similar way (compared to - oh I dunno - aluminium for example), and easy to make - although the structure will however be weaker than when made from the 'real carbon fiber'. And therein lies a slight marketing problem when you say what it's made out of because all it is, is basically reinforced plastic. But since it contains carbon fibres, you can legitimately call it 'carbon fiber' - and the consumer is none the wiser.
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What makes me laugh about where your post came from - and the general line of reasoning of you and many others like you on this forum - is that you're claiming I'm ill-informed or have an invalid opinion on the basis of how predictably easy
you are to market to. 'Fool me once' works on me. Apparently not for some.
I work in an education environment
I don't. You won't find a single iMac in our offices... except for the ones we used to have for the receptionists.
