HP P Class 450/500/550/600/650/700/750 Supplementary Manual page 4

initialization, and the difference between the fx4+ and fx2+ is handled by literally 1 line of code in the driver. The task
of dividing up the work between the "downstream" chips is a hardware function of the Host Interface chip.
(4) Geometry
Engines
HP Visualize
Geometry
AGP
Engines
Host
Interface
4.4 Mtri/s
Full DMA
Support
Figure 2. Block diagram of the VISUALIZE-fx4+. The VISUALIZE-fx2+ only differs by reducing the number of
geometry pipelines to 2, with a theoretical maximum of 2.2 Million Triangles/second
Although a similar naming convention is used, the VISUALIZE graphics products for the Windows NT environment are
different implementations than for the Unix Workstation systems. The underlying architecture is the same. In
particular, the Host Interface chip and the Rasterization chips are different in the Personal Workstation systems than
in the Unix Workstation systems. In addition, the Windows products include VGA graphics for Windows compatibility
when booting and for full-screen DOS mode.
In the block diagrams in Figure 1 and Figure 2, the theoretical maximum throughputs of the chips are shown. Actual
throughput measurements and the predicted effects on application performance are addressed below.
Display List or Immediate Mode with OpenGL
There are 2 fundamental types of rendering with OpenGL: Display List and Immediate Mode. Many applications use
a mixture, but most are predominately one or the other.
In immediate mode, the application calls OpenGL to draw a primitive (e.g., line or polygon) or modify the hardware
state (e.g., line color or a transformation matrix). The operation is performed, for all intents, " immediately," and the
driver does not keep a copy of the primitives.
In display lists, the application tells OpenGL to create a copy of the data that it is sending. The creation of the list is
called " compiling" the display list, and the drawing from the display list is known as " executing" the display list.
Because the OpenGL driver can store the information in a format that is the most convenient for the hardware, the
03/12/99
HP VISUALIZE fx4+
Frame Buffer
18 MB SGRAM
HP Visualize
Raster
Engines
800 Mpix/s
HP Visualize
Texture
Engine
70 Mtex/s
Optional Texture Acceleration Module
RAMDAC
Texture Memory
16MB SDRAM
HP 3