It's What's Under the Hood that Counts!

When Microsoft announced the Pocket PC most of the publicity went to the obvious changes in the user interface and the addition of applications such as Pocket Word and Excel, Microsoft Money, Windows Media Player and Microsoft Reader. Largely ignored by the press was the engine under the hood – the fact that these new “Windows Powered” devices used an improved version of Microsoft’s embedded systems operating system, Windows CE 3.0. This article looks at some of the more important enhancements to the new version of Windows CE and discusses how they affect the Pocket PC’s off-the-line performance.

More efficient memory management

With previous versions of Windows CE, users had to go to the Control Panel to adjust the balance between storage and program memory. You can still do this on the Pocket PC, but Windows CE 3.0 lets the Pocket PC automatically adjust the amount of RAM used for file storage and program execution based on the needs of the applications you are running. Because of this, users are able to run and switch between applications more smoothly than with the previous Palm-size PCs. In addition, when your system runs low on memory, you are prompted to close some applications. Also, the new Find feature lets you search for large files and delete them to free up memory.

Faster searches

Microsoft has completely revised the Find feature, accessed from the Start menu. Now you can search all the data on your Pocket PC in seconds where it used to take minutes on the Palm-size PCs. You can also perform these fast searches on specific types of data, including Contacts, Calendar appointments, Tasks, Pocket Word or Excel documents, and more.

Faster multitasking

The Pocket PCs continue to support multitasking. Multitasking is the ability to run more than one application at once. Since Microsoft used Windows CE 3.0 as the core operating system for the Pocket PC, multitasking is more efficient. Windows CE 3.0 reduces the amount of time required to switch between programs to 1/5th the amount of time it took in Windows CE 2.x. You will enjoy this feature when you want to play music at the same time you are working on your Pocket PC. Overall, the system seems to be smoother in the responses to user input due to this enhancement.

Faster connectivity

The Pocket PCs and ActiveSync 3.1 add USB (Universal Serial Bus) synchronization support. USB offers faster and easier synchronization than using the serial port. I believe that synchronization is about twice as fast using USB compared to using the serial port at 115.2k baud. You can still use the serial port or infrared if you want to.

Faster program execution

Prior to the release of the Pocket PCs, two types of CPUs were primarily used in Windows CE devices: SH3 processors made by Hitachi and MIPS processors made by NEC. The SH3-based Windows CE Handheld and Palm-size PCs use 16-bit instruction sets for all programs. The MIPS-based Palm-size PCs use 32-bit instructions. Without going into technical detail about what 16 or 32-bit instructions are, the fact is that 16-bit instructions allow the system to execute programs faster. In addition, programs written for 16-bit instructions are smaller than 32-bit programs. One final preliminary point, you can have a 32-bit CPU that uses a 16-bit instruction set. The key issue is the size of the instruction set. All Pocket PC CPUs are 32-bit processors, which refers to the size of the memory which the computers are able to access in one CPU cycle.

Future MIPS16-based Pocket PCs, including the Casio E-115 and Compaq 1550 now use the 16-bit instruction set for all programs. This helps make them faster than before by reducing the size of the instructions needed to execute a program. The SH3-based Pocket PCs, including the HP Jornada 545, continue to use 16-bit instructions (although the Jornada has a 32-bit processor). Compaq’s iPAQ H3600 is currently the only Pocket PC to use a StrongARM 32-bit processor. However, the ARM Pocket PCs use the ARM 16-bit instruction set called Thumb. This increases the performance of the ARM based Pocket PCs the same way MIPS16 does. Overall the decision to switch to 16-bit instructions will make the Pocket PCs faster and more efficient all at the same time.