Geometry Performance
Here are the geometry performance differences between the boards using a Difuse + Specular Lighting test from RightMarkD3D
ATI R580 Geometry Performance
|
Fixed Function T&L |
VS1.1 |
VS2.0 |
VS2.0 Static FC |
VS2.x Dynamic FC |
X1900 XTX |
91.2 |
87.7 |
87.5 |
81.2 |
55.6 |
X1800 XT |
87.2 |
84.2 |
84.7 |
77.7 |
53.4 |
X850 XT PE |
59.9 |
58.3 |
58.3 |
51.7 |
|
frames per second
ATI R580 Geometry Performance Diff 

|
Fixed Function T&L |
VS1.1 |
VS2.0 |
VS2.0 Static FC |
VS2.x Dynamic FC |
X1900 XTX to X1800 XT |
4.6% |
4.1% |
3.4% |
4.5% |
4.1% |
X1900 XTX to X850 XT PE |
52.3% |
50.3% |
50.1% |
56.9% |
|
percentage
The performance differences between the X1900 XTX and X1800 XT
herald no surprises as they are roughly around their difference in theoretical
rates, indicating that there are no alteration to the vertex shader engines. The
performance difference between the X1900 and X850 is in the 50%-60% range, but
for the most part this is a little below their theoretical rate differences.
ATI R580 Geometry Performance 2
|
Ambient |
Diffuse (1 point light) |
Diffuse (2 point lights) |
Diffuse (3 point lights) |
Diffuse + specular (1 point light) |
Diffuse + specular (2 point lights) |
X1900 XTX |
307.0 |
231.9 |
160.9 |
122.4 |
149.1 |
84.9 |
X1800 XT |
293.6 |
227.9 |
154.2 |
117.7 |
143.9 |
81.9 |
X850 XT PE |
141.9 |
140.5 |
98.0 |
79.5 |
113.5 |
68.5 |
frames per second
ATI R580 Geometry Performance 2 Diff 

|
Ambient |
Diffuse (1 point light) |
Diffuse (2 point lights) |
Diffuse (3 point lights) |
Diffuse + specular (1 point light) |
Diffuse + specular (2 point lights) |
X1900 XTX to X1800 XT |
4.6% |
1.8% |
4.4% |
4.0% |
3.6% |
3.7% |
X1900 XTX to X850 XT PE |
116.3% |
65.1% |
64.1% |
54.0% |
31.3% |
23.9% |
percentage
Again, with the range of differenct vertex shader operations
here the performance differences between the X1900 XTX and X1800 XT are hovering
around their theoretical differences. The performance differences between the
X1900 and X850 are a little different though, with the ambient test favouring
the X1900 significantly, while the specular tests favouring the X850
architecture, such that it has a performance deficit here that's less than their
theoretical differences.