The Radeon HD 3600 series was based on the codenamed RV635 GPU , packed 378 million transistors on 55 nm fabrication process .
The Radeon HD 3600 series was had 128 - bit memory bus width .
The Radeon HD 3600 series was based on the codenamed RV635 GPU , packed 378 million transistors on 55 nm fabrication process , and had 128 - bit memory bus width .