AMD: R8xx Speculation

How soon will Nvidia respond with GT300 to upcoming ATI-RV870 lineup GPUs

  • Within 1 or 2 weeks

    Votes: 1 0.6%
  • Within a month

    Votes: 5 3.2%
  • Within couple months

    Votes: 28 18.1%
  • Very late this year

    Votes: 52 33.5%
  • Not until next year

    Votes: 69 44.5%

  • Total voters
    155
  • Poll closed .
Not much obviously -- NV40 and G70 series shared a whole ALU for it, but it's the sampling that is the dirty work, IMHO.
 
Not much obviously -- NV40 and G70 series shared a whole ALU for it, but it's the sampling that is the dirty work, IMHO.
The addressing in NVidia's older GPUs ALUs is really just texture coordinate interpolation (calculation of the current pixel's texture coordinate, based on the 3 corners of the triangle and the texture coordinates at those 3 corners). Which the current GPUs also do in the multifunction interpolator ALU.

b3d92.gif

That's the "Project" part.

The TA part of NVidia's current GPUs is taking the coordinates, LOD and bias information to work out the address in RAM of a texel. That's the LOD and Address lines.

Jawed
 
When you said that HD4770's performance is all the evidence we need that RV730's TUs were squandered.

I think that if RV740 had only 320 SPs but the same number of TUs, then it would ony lose 5-10% of performance or so with AA/AF enabled.
That may well be true.

My assertion is that RV730 with 4 clusters with 4:1 ALU:TEX, instead of 8 clusters 2:1, would perform the same. But, not knowing the effect on most games of fp16 texture filtering (even at budget gamer settings?) I'm leaving a question mark over that conclusion.

In games with no fp16 filtering we can see this is probably true, because RV670 has exactly that configuration. HD3870 has more bandwidth and twice the colour rate of HD4670, though, but it does have the same Z rate. Generally HD3870 was slightly faster than HD4670 - don't know if things have changed.

Jawed
 
from 3dcenter ([fu]121Ah@work ):

8 memory chips on the front (can be seen on the old picture, or?) and 4 memory chips on the bag side (new picture) => 384bit ???
 
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