HP P Class 450/500/550/600/650/700/750 Supplementary Manual page 5

graphics throughput for display lists is almost always higher. Display lists are very effective when the same data is to
be displayed multiple times. Good examples are an architectural walk-through of a building or a fly-through of a
complex mechanical assembly.
Nevertheless, there are compelling reasons for some applications to use immediate mode. In general, immediate
mode is an easier programming paradigm for an application programmer.
For a large model, the display list itself could use many megabytes and is a duplicate of the model already in the
application controlled memory. So an immediate mode application may require less memory than display list, and this
could be the difference between being able to work on the model at all in a system with a maximum memory
configuration of 2 GB.
Immediate mode is useful if the data changes significantly from frame to frame – for example, when displaying time-
varying scientific data.
Examples of applications that run on Windows NT that are primarily Display List include Unigraphics and SDRC's
IDEAS suite of applications. Examples of immediate mode applications are PTC Pro/E, Kinetix 3D Studio Max, Avid
SoftImage, and Alias/Wavefront Maya.
characteristics: while PTC Pro/E is primarily immediate mode, PTC Pro/Designer is a display list application.
Performance Characteristics of the VISUALIZE fx+ Family
Since the feature set is the same, the distinguishing characteristic between members of the family is performance in
two areas: how much geometry acceleration and how much texture acceleration.
To illustrate the differences, the following measurements were taken on a system with a 450MHz Xeon processor and
the Intel 440GX chipset, using a tool called "glperf" created by the OpenGL Performance Characterization (OPC)
project.
Figure 3. Triangle Strip Display List Performance
6000000
5000000
4000000
3000000
2000000
1000000
0
0
In application workloads that we have analyzed, most average triangle sizes are less than 25-pixels. While most data
sets have large polygons as well, the small average size is due to approximating curved surfaces with a set of
triangles.
03/12/99
The same company may produce applications with different rendering
10 20 30
Triangle size in Pixels
40 50 60
fx6+
fx4+
fx2+
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