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.