The Performa 500 is an CPU upgrade kit from Evergreen Technologies designed to update older Pentium II's and Slot 1 Celerons to 500Mhz of CPU power, allowing you to run the latest and greatest software. When the Performa 500 showed up on our doorsteps, we wondered how this thing updates an old computer? At first we thought it was some kind of "overdrive" processor. Opening the package revealed that the Performa 500 is nothing more than a PPGA Celeron 500 on a Slot Kit.