'Unreal' and 'Quake2' improve vastly with memory clock increments, percentage wise. The framerate at 110MHz memory clock expressed as a percentage of framerate at 190MHz memory clock is tabulated as shown:
'Unreal'
|
'Expendable'
|
'Quake2'
|
67%
|
74.5%
|
65%
|
32-bit rendering at 1024x768 is bandwidth limited with 'Unreal' and 'Quake2', albeit for different reasons. Other than the doubling of framebuffer and z-buffer bandwidth, which is to be expected, 'Unreal' uses textures that are, on average, of higher resolution. This increases texture bandwidth. 'Quake2', a simple game by 1999 standards, creates scenes at a much faster rate compared to 'Unreal' or 'Expendable'. This, in turn, produces a generalized increase in all aspects of bandwidth (framebuffer, z-buffer and texture). 'Expendable' is not bandwidth limited as texture load is lighter than that of 'Unreal'.
The graph shows 16 and 32-bit rendering on 'Unreal' and 'Expendable' at high resolution. Note that 16 and 32-bit trendlines, initially spread far apart, gradually converge as memory clock rises. In every instance, 'Unreal' incurs a greater performance penalty for 32-bit rendering than 'Expendable', in large part due to its heavier texture load. At high memory bandwidth, 'Expendable' offers practically 'free' 32-bit rendering. At a memory clock of 190 MHz, 32-bit frame rates expressed as a percentage of 16-bit rendering is as follows:
Game
|
16-bit
|
32-bit
|
percentage
|
Expendable
|
35.3
|
36
|
98.1%
|
Unreal
|
32.2
|
35.3
|
91.2%
|
Quake2
|
64.6
|
70.8
|
91.2%
|