VRM Bypass Circuitry for use with G4 Cube
When installed in a PowerMac G4 Cube, the Dual PowerForce G4 '47 also features exclusive VRM Bypass circuitry. The original Apple VRM ("voltage regulator module"; also known as the DC/DC power supply card) is incapable of providing sufficient power for reliable operation at clock speeds faster than a single 1.2 GHz 7455 CPU. A dual CPU in the Cube was impossible, until now.
With the new PowerForce G4 '47 card installed, the Cube's original VRM is no longer the power source for the CPU. Instead, the CPU card uses its own power supply circuit. This greatly extends the life of the VRM, as the demands on the VRM are significantly less. In addition, the CPU power supply, since it is located on the card, is cooled by the internal Cube heatsink and the Cube's airflow. The original VRM, conversely, is located in one corner of the Cube, and has virtually no airflow.
By including this exclusive circuit on the Dual PowerForce G4 ‘47, PowerLogix has not only succeeded in extending the life of the Cube's weakest point, but has at the same time created the fastest, most powerful Cube ever.
