I'm torn about the Raspberry Pi project. On the one hand, it's awesome that the group is developing a very low cost ($25 and $35 goal price points) ARM based computer with some rather nice specifications (clock speed, RAM, USB, Ethernet [on $35 model], 3d accel, etc) but the way they're going about it somewhat rubs me the wrong way.

Broadcom makes the ARM processor (BCM2835) but hasn't released any type of datasheet. It uses package-on-package memory, which is rather difficult for many assembly houses to deal with and requires rather large orders in order to obtain memory from suppliers due to constrained supply lines. The Broadcom GPU that's integrated uses closed source drivers and in order to get legal access to the multimedia hardware IP blocks you are required to buy a license (RasPi says they'll include a few of the most often used codec licenses with purchase, but not all). The boot process is yet another convoluted weird way of doing things: the GPU runs first, executes a first stage bootloader, then dumps you over to the actual ARM core for booting Linux.

In order to manufacture their 6 layer (originally they said 4 but that's not appearing possible) board, RasPi is using blind, buried, or partial vias which raises the cost of the bare board and limits who can manufacture it. They're also not even connecting all pins on the processor, some GPIO won't be connected to anything and thus will be unused. These tiny pitch BGA parts are awesome if you've got constrained spaces to fit in and you have access to seriously advanced manufacturing capability and can use 8+ layer boards. Otherwise, they're a pain!

The RasPi foundation is getting special pricing on almost all of their parts. They're buying in the 10,000 quantity but (at least on some parts) appear to be getting 1,000,000 quantity pricing. They have publicly said they are not getting any sponsorship or free parts, which is good to hear based on their very low price point goals for the finished product.

Although Eben has said (in answers to Slashdot questions) that the layout and schematics would be open with "A qualified yes," that's dependent upon the final board design being able to be exported to something like Eagle. He also throws in some other verbiage that makes me unsure what will really happen. (And yes, I understand I won't be able to build one myself, even if I had mad hot air rework skills, the pitch on some parts are remarkably small and POP is a nightmare even for automated robotic assembly shops.)

But in the end, my biggest concern is that the $25 and $35 prices won't really happen. There's been mention of a "give one get one" program at first (so you have to pay for 2 in order to obtain one) where the one you "give" will be provided to school children. But there's not been mention that I've seen of when the one you "give" will be actually given. Mostly, for $25, leaving the RasPi foundation with no profit, they need (my personal SWAG on cost) about $15 in parts (including circuit board), maybe $8 in labor to assemble (including all tooling costs being rolled into the per unit cost), and that leaves about $2 to cover testing and warranty replacements (2% warranty rate is $0.50, 4% is $1). That's crazy cheap! And it requires a very low failure rate under warranty, let alone the costs associated with fulfilling the warranty replacements (emails, phone calls, shipping, etc aren't included).

I don't think $25 and $35 price points are sustainable in a break-even or profit making enterprise based on the goals and current public information for the Raspberry Pi. I do hope I'm wrong.



29 September 2011