Counting the chips in mobile computers

What do you want in a mobile computer?

How much performance do you want to give up for longer battery life? Would you buy a clunky mobile computer that can run anything you throw at it? If you're the envy of the digerati when you walk down the street with your new phone, but you can't use it to make reservations at Nobu, are you still cool?

Chipmakers are struggling with these questions as well as how to adjust their recipes for the future of mobile computing. It's not so much the about chips themselves, but how you use them.

The current model for smartphone chip design used by companies like Texas Instruments, Samsung, and Freescale Semiconductor is to minimize power consumption by relying on an ARM applications processor for many tasks, but spreading much of the work around smaller components called accelerators that are activated only when needed.

Intel acknowledges the special role that hardware accelerators play in this market, because a modern general-purpose processor like the Core 2 Duo simply won't fit into a handheld device. But it argues that the role of accelerators should be somewhat limited to maximize software compatibility, and that the processor, such as its low-power Silverthorne and Moorestown designs, should be able to take on a great deal of work.

So which approach is best-suited for the next generation of mobile computers? Modern smartphones offer snappier performance and can run all day, but the increasingly sophisticated software that people want on these devices can overwhelm the system and cause compatibility issues. Running a wide variety of software won't be a problem for devices based on Silverthorne and Moorestown, but Intel still has a ways to go to allow its customers to build devices that are design showpieces like the iPhone.

One of Intel's most important goals over the next five years is to establish itself as a silicon supplier to future manufacturers of ultramobile computers, whether those are smartphones, Mobile Internet Devices, UMPCs, or some other design that emerges from that soup. It's already tried this once, attempting to break into the mobile phone market with an ARM-powered chip that was a model of integration, but a flop with customers.

ARM and its partners enjoy almost complete control over the current smartphone market and are eyeing the evolution of the platform just as closely. This is the next growth engine for personal computers, something made extremely clear last year with the steps taken by outsiders such as Apple and Google to gain a foothold.

Eye on power consumption
The mobile phone chip suppliers evolved their strategy by focusing first and foremost on power consumption, a luxury they were afforded by the relatively simple software run by most mobile phones up until fairly recently.

The basic idea is that most of the time, your phone or mobile computer isn't doing a whole lot. But every now and then, you need a performance boost to fire up a video clip, download something from the Internet, or take a picture. In the ARM community, chip companies deliver this performance with a complicated concoction of multiple processing cores that only handle one specialized task, such as video encoding.

"What happens is that each task runs on the specific engine that is much better optimized from a power generation standpoint," said Avner Goren, worldwide director of cellular systems market for TI. "Offloading video from a central CPU to a video and imaging accelerator decreases the power generation."

Intel is used to integrating as many of those kinds of functions as possible into its PC chips and might have been expected to bring that same approach to this new battleground. But as it prepares to roll out Silverthorne, and later Moorestown, power consumption requirements are forcing Intel to acknowledge that it can't do everything with a single chip.

"We don't expect everything to be done by the general-purpose processor," said Ticky Thakkar, director of Intel's ultramobile group platform architecture and an Intel fellow. "(But) you need it for compatibility reasons; you need the same software that runs on a PC to run on a handheld device."

As with many decisions in chipmaking, the question is one of engineering trade-offs. ARM, TI, and the other smartphone chip companies are trying to step up to build more powerful computing devices, while Intel is trying to cram a PC into a handheld. Their respective starting positions dictate the philosophies to a great degree.

Why should you care? TI argues that its approach results in better battery life and can actually improve the responsiveness of the hardware, since the various accelerators band together to spread out the load.

"When you are using an architecture of multiple cores and multiple engines, and you offload the multimedia tasks to the coprocessors, the ARM (core) is more responsive because it's not loaded," TI's Goren said. This approach also has power benefits that allow device builders to push the envelope of slim and stylish design.

Thakkar concedes that point, but notes that a more powerful CPU can handle popular software-based codecs like Flash or Javascript that don't need an accelerator. Flash is hard to find on a mobile phone. The alternative is Adobe Systems' Flash Lite technology, which isn't bad but isn't the same as the PC version of Flash.

This is the heart of Intel's pitch to mobile device makers like Nokia and Apple: we'll be able to support anything you currently enjoy on your PC, on your mobile phone. Not necessarily at the snappy performance levels you're used to on a Core 2 Duo laptop, but Intel wants to deliver a PC-like experience on a mobile phone.

A smartphone is no PC
As advanced as smartphones have become, they're not overtaking the PC on any benchmarking applications anytime soon. And as Intel's manufacturing operation continues to crank out smaller transistors, and integrates more and more of them onto a processor, Thakkar thinks it's going to be hard for other players to match Intel's combination of software compatibility and performance.

But then again, is that what you want from a mobile phone, a little PC? "A laptop is not a cell phone. When I boot my laptop, I've trained myself to go get coffee. When I switch on a cell phone, I expect that I can make a call in seconds," Goren said. Running PC software might be nice in theory, but TI and the mobile phone companies think that software written for the PC is too bloated for the phone environment.

This isn't a one-size-fits-all market. Consider just how many types of mobile phones there are, from iPhones to Voyagers to BlackBerrys to Hiptops. Those phones all require a different balance between performance, power consumption, battery life, and software requirements. But for the most part, the laptop form factor isn't all that much different between a Pavilion, an Inspiron, or a MacBook.

Phone makers like Nokia, Motorola, and Apple will decide how this battle plays out. For smartphones to really evolve into mobile computers, they'll need to ensure that software written for one operating system will run across many devices--which isn't always the case now and is a large reason why Google is getting involved. But for Intel to find the elusive source of growth outside the PC market it so desperately needs, it's going to have to deliver on the audacious goals it has set for power consumption.

Silverthorne, due out in the second quarter, isn't quite the answer. Moorestown, which is expected to arrive around 2010 and consume 10 times less power than Silverthorne, could be. If Intel can pull that off, it would put Moorestown down on the milliwatt range currently occupied by ARM's chips, with performance that should rival anything from TI, Samsung, and the like.

"We've made these jumps where we've taken order-of-magnitude leaps," Thakkar said. For Intel to find the next big source of growth that has eluded its grasp this entire decade, it will need to do that again.