Sorry had to run out and pick up a few socket A coolers...
any how I would like to direct your attention to a few things if I may:
1. (a few illustrations from ATI's released roadmap)
Slide 6 of 22:
<center>
<img src="
http://www.radeonfaq.com/rv200/3dengine.gif">
</center>
Here we see that the 3 TMUs remain intact in the RV200, within the Pixel Tapestry block we see two renderers (pipelines) each with 3 texture units.
then onto slide 13 (of 22), paying particular attention to the third entry:
<center>
<img src="
http://www.radeonfaq.com/rv200/rendline.gif">
</center>
This simply illustrates that the R200 will have twice the rendering piplines as compared to the Rv200 (4 vs 2).
then onto slide 14 (of 22), again paying attention to the third line:
<center>
<img src=http://www.radeonfaq.com/rv200/6tex.gif">
</center>
This is what truly solidifies the deal, similiar to how the GF3 with its 4 pipes and 2 texture units is able to "combine" each renderers lines and TUs to render up to 4 textures per pixel per pass. If the R200 is to have the same amount of both rendering lines (4) and texture units (4?) then the ability to do 6 textures per pixel per pass becomes nearly impoosible unless ATi has bent the laws of mathematic equations so that (4*2)/2 = 6. The ONLY real possible solution to this is that the R200 has 3 TUs per renderer (4*3)/2 = 6 = True.
2. Now onto ATI's official documents on SmartShader:
(
http://www.ati.com/na/pages/technology/hardware/smartshader/smartshader_white_paper.html )
Listed as one of the key improvments in the R200:
"
Support for up to six textures in a single rendering pass, " again confirming what was already pointed out in slide 14 of ATI's Roadmap (see above.)
The following two pictures give an visual representation of this process:
<center>
<img src="
http://www.radeonfaq.com/rv200/pixshad.jpg">
</center>
<center>
<img src="
http://www.radeonfaq.com/rv200/pixshad2.jpg">
</center>
Now, scrolling down the page to "SMARTSHADER Advantages", in a comparison of DX 8.0 Pixels Shaders, PS (as utilized the the current GF3) we see the following:
- DX 8.0 PS supports a Max Texture input of 4 where as PS in DX 8.1 supports upto 6 (an increase of 50%, or 2),
- DX 8.0 PS under Max. Program Length, supports 12 instructions:
- 4 Texture sampling, 8 color blending
- DX 8.1 supports up to 22 instructions in Program length, the same amount of instructions are used in color blending, however again we see a 50% increase in texture sampling (up 2 from 4) to equal 6 and also includes 8 new instructions, being texture blending.
Taken all these facts into consideration and the very uniform increase of 50% in instructions and texture support. These increases in support over DX 8 (4 texture untis for example) can NOT be simulated directly without the inclusion of addition hardware (TUs), this is why Reactor Critial's assumptions as to the amount of texture units is very flawed ... to go any further into details..well, Tuesday is approaching soon enough...