Compaq Professional 5100, Дополнительное руководство

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T
ECHNOLOGY
B
RIEF
(cont.)
10
ECG066/1198
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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.
CPU
Memory
Controller
Graphics
Controller
Monitor
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
SCSI
Controller
Di
s
k
PCI Slots and
other Devices
PCI
Controller
PCI Slots and
other Devices
PCI
Controller
Graphics
Controller
Figure 7. The new Highly Parallel System Architecture allows the processors and graphics controller to
access two separate memory buses concurrently.