You need software. These aren't processor upgrades that replace the stock CPU, they are accelerators that go in the PDS slot and operate alongside the stock CPU (which can't be removed). During the boot process, a Sonnet extension offloads execution from the PowerPC 601 onto the card in the PDS slot. Without the software, the card just wastes electricity and generates heat. It doesn't actually do anything. However, the software is very simple - no control panels, just an extension. The software automatically detects the speed of your system bus and sets the CPU speed accordingly.

Download it here: http://www.sonnettech.com/support/downloads/processorupgradecards.html#crescendoencore

Peace,

Drew