- Oct 3, 2008
There are several benefits.The reality is that a future CPU board (expensive) will likely need it's own peripheral board (much less expensive) and would need to be sold as a pair.
Honestly, if that's the case, then there is absolutely no benefit in having a daughter board for the CPU. The whole point was to have a separate board so that the keyboard, face buttons, ports, etc could all remain without having to need a new board.
The CPU board is an expensive (7 layer?) part with a particularly expensive component (SoC). However it is not subject to wear and tear on ports - no moving or frequently re-plugging parts. The odds of it failing post production are relatively low.
The peripheral board is an inexpensive (2 layer?) part with many inexpensive components (Plugs & contacts). It is subject to wear and tear from plug insertions, keyboard presses, etc...
If a machine comes back on a warranty claim, being able to replace the peripheral board and keep the CPU board is beneficial.
Also, during production, an error on one board doesn't fail the whole set. I.e. if a solder line to a plug gets goobered, it doesn't scrap an SoC. By using separate components into two categories (complex CPU board) and (simple peripheral board) it should increase the yield of usable parts.
With the 3G module on the peripheral board, different peripheral boards can be efficiently produced by region or cost needs.
1. Peripheral board without phone module (cheap)
2. Peripheral board with Euro 3G
3. Peripheral board with US 3G
4. Peripheral board with 4G (very expensive)
Then they all got mated during assembly with the same SoC/CPU board.
You've gotten all upset about the USB 3.0 OTG connector and your fears around durability. If it fails, you can replace the peripheral board relatively cheaply compared to what it would cost if it were all on the same board.
Yes, in theory, a new SoC could be found and mated to the peripheral board. In order to expect the peripherals to all play nice with the SoC, though, the SoC would need to be of a similar generation of peripherals. Don't expect an SoC produced 2-3 years from now, that nobody here has even imagined the specs of, to play nice with a peripheral board generated on today's generation of SoC. It would be like expecting today's current desktop CPUs to plug into a PC from 1987 and expecting the one from 1987 to support all of it's features. Back in 1987 they had no idea of what is being used today.
In theory the current peripheral board being produced might be able to 'play nice' with something like Bay Trail, but that is a lot of dev work for a niche subset of a niche audience. Not likely to happen any time soon.
The modular design does have some great benefits though - mostly surrounding design, production and repair costs and product options (none/3G/4G).