Editing Emotion Engine (section)

=== External interface ===
Communication between the Emotion Engine and RAM occurs through two channels of [[DRDRAM]] (Direct Rambus Dynamic Random Access Memory) and the [[memory controller]], which interfaces to the internal data bus. Each channel is 16&nbsp;bits wide and operates at 400&nbsp;MHz DDR (Double Data Rate). Combined, the two channels of DRDRAM have a maximum theoretical bandwidth of 25.6&nbsp;Gbit/s (3.2&nbsp;GB/s), about 33% more bandwidth than the internal data bus. Because of this, the memory controller buffers data sent from the DRDRAM channels so the extra bandwidth can be utilised by the CPU.

The Emotion Engine interfaces directly to the Graphics Synthesizer via the GIF with a dedicated 64-bit, 150&nbsp;MHz bus that has a maximum theoretical bandwidth of 1.2&nbsp;GB/s.<ref>Diefendorff 1999, p. 5</ref>

To provide communications between the Emotion Engine and the Input Output Processor (IOP), the input output interface interfaces a 32-bit wide, 37.5&nbsp;MHz input output bus with a maximum theoretical bandwidth of 150&nbsp;MB/s to the internal data bus. The interface provides enough bandwidth for the PCMCIA extension connector which was used for the network adapter with built-in P-ATA interface for faster data access and online functionality. An advantage of the high bandwidth was that it could be easily used to introduce hardware extensions like the Network Adapter with built-in IDE HDD support or other extensions to extend functionality and product lifecycle which can be seen as a competitive advantage. In newer variants (like the slim edition), the interface would however, offer vastly more bandwidth than what is required by the PlayStation's input output devices as the HDD support was removed and the PCMCIA connector design was abandoned in favor of a slimmer design.