Needless to say, this has been one fun Spring so far. I think that things are going to get even more fun once ATI joins the fray. A couple of things here:
Mintmaster, your whole "look at R200 vs RV350" argument is a bit flawed, mainly because we are talking about DX 8.1 hardware vs. DX 9.0 hardware, and the HUGE differences in architecture between the two chips. Yes, R200 was a 4x2 pipeline affair... but it was DX 8.1! It had no floating point pixel pipelines! Not to mention the Vertex Shaders on that were 1.1, while the VS on the RV350 is 2.0! Huge differences, so you can't really paint a big picture about transistor counts using these two chips. If there was ever an "apples and oranges" argument, this is it.
I think it is agreed on that the R420 will not support FP32 and PS 3.0. Both of those options do require more transistors. Now, ATI has said in the past that they could have done full FP32, but it would have required anywhere between 5% and 10% more transistors. Rendering FP32 at a decent speed would have required even more transistors, so the decision to go FP24 for the first few generations of chips was a very good plan, as it did save a lot on transistor counts, and those transistors can be used elsewhere for things like better visual quality (higher AA levels) and making a faster shading chip (1 full and 1 partial shader per pixel pipeline vs. only having 1 full shader). ATI has been working on the R420 chip for some time, and we can most likely take it that the pixel pipeline design has undergone some changes, most of which will help the overall speed and efficiency of their operation (as well as adding another 4/8 pipelines to the mix- giving chips with either 12 or 16 pixel pipelines). We can also guess that the vertex shader has also undergone a lot of work, and I wouldn't be surprised if it in fact was a VS 3.0 compliant piece of hardware. Current R3x0 chips have 4 VS units on board as is, and I can easily see them putting 6 VS units in there, which would give NV a run for its money in that area.
It is my opinion that the X800 will be slower overall than the 6800 Ultra, but that the X800XT will be faster than the 6800 Ultra in most operations. Of course, the X800XT will not support PS 3.0. This may or may not be a sticking point. One big point will be the power draw and heat given off by this chip. I am also betting that it will run cooler and consume less power than the NV40. I also believe that the X800XT will run at over 500 MHz. ATI does not sit on their hands, and the design groups that currently work at ATI are truly second to none.
So, I think ATI will continue to have the performance crown this summer after the dust settles, but it will not hold the overall feature crown. One other thing to consider is that the NV40 architecture still looks like it can run FP16 at significantly higher levels of performance over FP32 rendering, so in applications which utlize partial precision, the NV40 could see some hefty speed increases over pure FP32 (this really only stands to reason).
So, what is it going to be? I have no real clue, cause I haven't seen the new ATI hardware! All I know is that I believe consumers will have two very solid architectures to choose from this buying season, and I do not think that either will disappoint.
One area that could truly define each company is their midrange offerings. With NVIDIA set to release NV4x variants at the midrange and low end, what will ATI do? The FX5200 proved to be a great seller for NVIDIA because it did support DX9 fully (but of course without the speed to actually run it well... at all!). However, major OEM's and many mainstream consumers bought up the FX 5200 in droves, while ATI's 9200 did not sell nearly as well. These feature checkboxes are very important to OEM's trying to sell a computer to the "unwashed masses" who don't particularly know a whole lot about computer hardware and many of the terms associated with it. The 4 pipeline and 8 pipeline NV4x variants could very well compete with the current crop of R350 and RV360 chips on the market, and support PS/VS 3.0 to boot. What do you think the average buyer will choose?
Big questions, and we won't know the answer until at least Christmas!
