Pocket PC, XScale hit a generation gap

Early buyers won't get all the power they bargained for in the latest Pocket PC-based handhelds. A generational mismatch in the gear is taking the pluck out of performance.

Richard Shim Staff Writer, CNET News.com
Richard Shim
writes about gadgets big and small.
Richard Shim
4 min read
Early buyers won't get all the power they bargained for in the latest Pocket PC-based handhelds.

A generational mismatch between Microsoft's Pocket PC 2002 operating system and Intel's XScale PXA250 processors included in new handhelds is resulting in devices that don't deliver all their potential performance, according to Microsoft.

The new devices, which contain Santa Clara, Calif.-based Intel's 400MHz XScale PXA250 processors, perform about as well as older Pocket PC-based devices that use 206MHz StrongARM SA-1110 chips on similar applications.

"Fundamentally, devices don't seem to be demonstrating the performance improvement that many were expecting," said Ed Suwanjindar, a spokesman for Redmond, Wash.-based Microsoft. "They're performing on par with existing StrongARM devices."

The lack of pizzazz could well turn into a marketing problem for Hewlett-Packard, Toshiba and others selling the new handhelds. HP's new iPaq H3970, released at the TechXNY trade show in New York this week, sells for $750. Except for the processor switch and new screen technology, it's basically equivalent to the older iPaq 3870, which sells for $100 less.

Pocket PC device manufacturers probably won't be the only ones facing these problems for long. Palm will release its first handhelds based on chips from Cambridge, England-based ARM this fall, and analysts say performance problems caused by software-hardware lopsidedness are inevitable.

Palm could face even larger problems showing off performance benefits. All Palm devices currently run on Motorola Dragonball processors, which top out at 66MHz, and will run on ARM chips initially through emulation, a method of translation that generally affects how well applications run.

"There will be some Palm apps that won't show a noticeable improvement when running on ARM-based platforms because of application emulation," said Kevin Burden, an analyst at market researcher IDC.

But in most cases on prototype boards, Palm is seeing a performance improvement using emulation, according to Palm Chief Competitive Officer Michael Mace.

"There isn't a big emulation penalty" in terms of performance, Mace said.

New chips, old software
According to Microsoft's Suwanjindar, the lack of improvement in performance can be attributed to Pocket PC not being fully updated to work smoothly with the new processors. The new Pocket PC-based devices from Toshiba and HP, which range in price from $599 to $750, use Intel's 400MHz XScale PXA250 processors. The chips are based on the fifth version of the ARM processor architecture, a chip design from ARM.

The new Pocket PC-based devices do feature new capabilities that were not built into previous handhelds. Toshiba's e740 Pocket PC handheld incorporates 802.11b wireless networking, which lets device owners share files and resources with a PC or computer network. The HP iPaq 3970 comes with remote-control technology that lets devices control up to 20 categories of home electronics devices.

Microsoft's Pocket PC 2002 OS, though, works best with chips based on the older, fourth version of ARM's architecture, like the Intel 206MHz StrongARM SA-1110 that's used in the vast majority of Pocket PC-based devices on the market. Thus, most applications run at about the same rate.

Suwanjindar declined to comment on when or if the Pocket PC OS would be updated for the new chips or whether Microsoft would offer free upgrades if the OS gets tweaked. Burden, though, said he didn't expect another version for some time.

Peter Glaskowsky, editor in chief of industry newsletter the Microprocessor Report, said it is not realistic to expect the performance of devices to double when the clock speeds of the processors they use double.

Glaskowsky, who uses an Apple Newton, added that software developers for Palm, a rival to Microsoft, will also run into performance issues as the Palm OS transitions to ARM microarchitecture in its recently released Palm OS 5.

Palm is jumping from one chip architecture to another--not just from one version to another of the same technology--which means it's a trickier gap to leap. In Palm's favor, however, will be the jump in processor speed. Most Dragonball-based devices use chips running around 33MHz.

In addition, handheld makers aren't just concentrating on boosting visible application performance, so benefits from the new chip aren't as tangible, according to IDC's Burden.

"In the case of XScale-based devices, manufacturers and consumers are also looking at the improved power management capabilities that XScale brings," Burden said. "Intel's XScale chip can scale the use of power to the level of performance needed by the applications that are in use."

Intel said consumers will experience performance improvements on some newer applications.

"As we developed (the XScale PXA250), a large percentage of the work went into streamlining power consumption on the system level and the CPU itself," said Mark Casey, a director of marketing at Intel.

Some of those areas include the performance of multimedia and security applications, which have shown a 40 percent to 60 percent improvement measured against internal benchmarks, according to Mark Casey. Not many multimedia applications are available on the market because devices have not been powerful enough to run them adequately.

Intel's focus will also be on XScale as StrongARM fades into the past.

The StrongARM SA-1110 processor, which runs at 206MHz, "is capped, done," said Intel spokesman Mark Miller. "But these new processors have headroom to grow."

The XScale processors for handhelds currently top out at 400MHz but have been demonstrated to hit clock speeds as high as 1GHz.