12. Overclocking Pocket PCs In Practice

PDAs fitted with XScale CPUs now permit a degree of 'tuning,' because the XScale is designed to operate out of the box at various clock speeds in order to optimize power consumption. When the CPU is idle, its speed is reduced automatically and then increased again as soon as it is needed.

Programs such as Advanced XScale CTRL by Matthew Pattman (wince.wibble-wobble.com,) utilize this feature. With this utility you can theoretically overclock all XScale PDAs by switching the CPU into continuous Turbo mode. In our test, for example, we were able to run the Ipaq H5450, the Dell Axim and the Toshiba e740 at 500 MHz with 100 MHz memory speed without any problem. The CPU benchmark figures increase in linear fashion as the CPU speed increases: 20% extra processor speed delivers 20% more performance. We were unable to get more than 500 MHz from our 400 MHz PDA.

The program also lets you change the memory speed (formula: 3.6864 MHz fundamental frequency multiplied by the L-value - see diagram on the right). It is therefore relatively straightforward to set a value of 117 MHz for the memory speed at a CPU speed of 472 MHz. Higher speeds are only possible with the Zayo AD600, which is able to reach 147 MHz memory speed and 440 MHz CPU speed.

These ramped up speeds are not possible with every device, as overclocking capability varies from one CPU to the next. But experimenting should not do any harm. In our tests, PDAs initiated a hard reset when they couldn't handle the increased speed. Although this not does not cause any damage to the hardware, all data and installed programs are lost. Intel specifically mentions that there is no warranty on Pocket PC processors that have been damaged through continuous overclocking.

Advanced XScale CTRL gets an extra 100 MHz from the Dell Axim.