Why has Xscale been delayed?Anyone hoping to buy PDAs with the new generation of Intel processors is likely to be disappointed as there's no software out there capable of using their whizzy new features. Intel announced the first of its new line of processors for handheld computers in February. Based on Xscale, Intel's ARM-based architecture, the PXA250 promised both higher speeds and greater power than the current generation of StrongARM-based processors. Fujitsu-Siemens was due to ship what would have been the first Xscale-based PDA, the Pocket Loox, in May, but the launch has been put back to June or July, fuelling speculation that technical problems with the new processors were to blame. The problem may in fact be more to do with the software. The specifications for the PXA250 certainly look tempting. A PXA250 running at 200MHz requires around half the power of the current top chip, the SA1110, running at 206MHz. The PXA250 can be cranked up to 400MHz, where it consumes the same amount of power as the SA1110 but delivering twice the speed, according to Intel's own benchmarks. But to get the full benefit of speed and power-saving features, the Xscale processors need to run specially optimised programs, which sadly are not yet available. Microsoft's current PDA operating system, Pocket PC 2002, is based on a Windows CE 3.0 kernel, which is optimised for a class of processors which includes StrongARM, but not Xscale. So the rumours that the first Xscale products don't run any faster than StrongARM are almost certainly true. Robbie Ray Wright, marketing director for the Microsoft Mobility Group EMEA, said: "Microsoft is dedicated to the ARM platform, but we have to have a single platform for developers to target." In other words, Microsoft only wants to release one operating system at a time, as it doesn't want its developers to have to write all its applications twice. So we won't see a Microsoft operating system that takes full advantage of Xscale until much later on. It may be that the next version of PocketPC, launch date unconfirmed, will make more use of the Xscale performance enhancements. But a source at Intel suggested that the CE.net kernel, on which the next version of PocketPC will be based, wasn't optimised for Xscale either. The follow-up to CE.net, based on a kernel known only by the codename Macallan, is closer to being Xscale optimised. And even that "wasn't where we want it yet," the source said. Macallan is not due out until 2003, and a Pocket PC operating system based on Macallan, and making full use of Xscale's speed enhancements, may not be out until the year after. Symbian claims that version 7 of its operating system for smartphones is optimised for Xscale. But in the PDA world, it's likely that the first Xscale optimised systems will be a version of Linux. Having only recently ported to StrongARM, Microsoft's main rival Palm is not likely to release a genuinely Xscale-optimised operating system any time soon either. Intel is working with embedded Linux company MontaVista on a version of Linux for Xscale-based PDAs. Though there is no date for a launch, it's not going to be hard to beat Microsoft or Palm to market. Tony Sica, Intel marketing director, wireless communications and computing group, said: "People have not worked out how to make the most of the exciting power of the Xscale processor platform. "It's the same situation you had when Pentium 4 came out - the software wasn't optimised to start with." IDC analyst Andy Brown criticised Intel for not making the Xscale chips available to software companies soon enough. He said: "Intel has been slow to bring Xscale to market, and it is not working as closely with the software manufacturers as it should be." Either way, the delay of the Pocket Loox won't be the first hitch on Xscale's long road to the mass market.