HP Professional 8000 Highly Parallel System Architecture for Compaq Profession - Page 10

ECG066/1198 TECHNOLOGY BRIEF (cont.) ... rate of 334 MB/s. The large amount of memory bandwidth consumed by monitor refreshing is not available to the processor and graphics controller for other tasks. In contrast, all graphics cards used in Compaq workstations use dual-ported memory that does not take bandwidth from the graphics controller. Monitor CPU Memory Controller Graphics Controller PCI Controller PCI Slots and other Devices Figure 6. Unified Memory Architecture used in the 02 workstation from Silicon Graphics, Inc. The new architecture being implemented by Compaq (Figure 7) allows the processor and graphics controller to access separate memory pools concurrently. Furthermore, the ELSA Gloria-L 3D graphics board and the Diamond Fire GL 4000 3D graphics board available with the new Compaq workstations have their own frame buffer and Z-buffer/texture memory. They do not rely on a common pool of memory for most data. Since data is accessed on two separate buses at the same time, the actual bandwidth is 1.07 GB/s for the memory bus plus the bandwidth of the graphics controller memory buses. CPU CPU Memory Controller Memory Controller PCI Controller PCI Controller Disk Graphics Controller PCI Slots and other Devices PCI Slots and other Devices SCSI Controller Figure 7. The new Highly Parallel System Architecture allows the processors and graphics controller to access two separate memory buses concurrently. 10