Apple gives the finger to the chipmakers

23 April 2008

Late yesterday, Forbes reported that Apple has decided to buy boutique chipmaker PA Semi. So, the conference call later today where Apple announces its results for the second quarter of 2008 is going to be interesting. And there will be a bunch of silicon suppliers wondering what's going wrong for them.

Discarding the possibility that Apple has decided the move to Intel, and its rejection of PA's PowerPC processor in 2006, has been an awful mistake and it suddenly needs to press the architecture reset button, the move by Apple suggests that the company is not all that happy with the shape of today's integrated circuit (IC) business.

One possibility is that Apple has decided it needs more in-house chip designers and buying PA was a quick way to staff up. That's not unusual in this business: it's a surprisingly common way of getting hold of people who can design the analogue circuits that most electronics engineers fear to touch. Even after you've bought in a bunch of processors and memory, there are other places a computer maker can use experienced IC designers to get an edge on its competitors. You don't see that much in the PC business but it's a lot more common in places like the phone market.

This particular team has a string of famous processors behind it, as it's the team led by former Digital Equipment Corporation architect Dan Dobberpuhl - responsible for the Alpha, famed for being the world's fastest processor for a while, and the StrongARM, which Intel ended up using to push its way into the PDA business before passing the design on to Marvell Semiconductor. With that kinds of background, it's hard to see this team being happy to work on glue logic. Apple might be able to lock the senior people in for a while but, if the project isn't a processor or something similarly complex, you would expect most of them to drift away quite quickly. So, it's fair to assume that Apple is serious about having its own processor design team, if not the PA processor itself.

PA's PWRficient design uses a number of tricks to get the power of a 2GHz processor down to manageable levels - below 20W rather than the 80W of a typical laptop processor. But what PA has today does not fit too well with what Apple is doing these days. It's OK for telecom basestations but even the best-case power consumption of 5W is too rich for a palmtop devices: you really need to be under 3W to stop the thing turning into an expensive hand heater. Forbes, quite reasonably, speculated that Apple wants the team to work on a processor for a future iPhone or mobile internet device (MID).

Apple's decision is not just a poke in the eye for Intel, which would have liked to sell its Atom into the world of MIDs. There are a ton of companies out there with processors based on ARM all desperate for a slice of the phone and MID markets. And it looks as though Apple looked at all of them and found them wanting.

Today, the iPhone uses an ARM-based processor from Samsung Electronics. The company has used a variety of similar processors in its iPod line-up over the years. PA made a big issue of its use of clock gating and power supply control - but similar techniques are in use on ARM-based processors. For example, ARM has its own software-controlled energy manager for the ARM11 that is broadly similar to PA's dynamic power supply control. You can buy tools from companies such as Calypto to insert gated clocks into circuits automatically, which lets designers do the much finer-grained clock control that PA claimed to have.

So, why take on the risk of doing your own processor when you have 20 people beating down your door to offer you one with broadly similar features? Because you think, with your own team, you can do a better job. The StrongARM was an example of what could be done with the ARM architecture if your focus was to get a much faster processor without driving up power consumption too much - and that was not ARM's focus at the time.

It would make sense for Apple to continue with ARM in this class of device simply because the software has now been ported to the architecture rather than trying to do an even leaner PowerPC. So, one option may be to get Dobberpuhl and co to do StrongARM 2, or to get them to have another go at the PowerPC architecture they already have and bear the cost of porting the iPhone software to that processor. Having gone through several architectural changes, Apple is getting pretty good at it. I'd opt for the ARM approach as that gives Apple the most room to manoeuvre if its plan does not come off.

Whichever way Apple goes, it's not good news for the mainstream chipmakers as this acquisition largely tells them that, whatever they are doing, Apple reckons it's just not good enough. It's not as if Apple will have a problem getting the resulting products made: there are a number of foundries who would only be too happy to take Apple's business.


....and doesn't Apple have an ARM architectural licence as well?

I think you're right - there's probably a lot of slack in most processor designs, in terms of MIPS per watt, which doesn't get addressed because of time to market issues, or a desire to keep the resultant design generic. If, on the other hand, you set a group of very experienced people to work designing a processor for a very narrow set of applications in which MIPS per watt really matters to the company's success, there's probably a lot you can do.

That's an interesting question: I nearly put that in, but then thought, if Apple has one, it was never disclosed. As a founding investor in ARM, there may well be a clause that provides Apple with the equivalent of an architectural licence. But I can't find a record of ARM saying Apple has one.

When Motorola (ie Freescale) took out an architectural licence, it was the second 'announced' architectural licence: the first being Intel (having taken on the DEC licence), which kind of hinted that either VLSI (now NXP) or Apple had something along those lines when ARM was first formed.