expletive said:
So youre saying its no easier for developers who have been working on G70s (or at least access to final hardware of it, or at LEAST developer friends who have worked with it
) for the past 8 months to work with the RSX (assuming that G70 is its heritage of course)? The learning curve and understand strengths/weaknesses of the design isnt improved over a totally new design like Xenos?
In the basics, no. When they had 9800s in their XB360 SDKs, if they wrote an engine that ran at 10 FPS, it'd port staight to Xenos with a substantial improvement.
The complexities of Xenos, the things that make it different, are eDRAM, MEMEXPORT, and US. US takes care of itself. eDRAM needs to be considered for AA and BW intensive tasks like alpha blending, so if you're not working on an intensive alpha-blended particle engine you don't really need to care about this. MEMEXPORT I don't think has any benefit for graphics rendering. I've still yet to hear some good examples of what it'll be used for! Regardless, it isn't essential, but an optional extra to get more than just the usual from the GPU.
If you don't use the special features of Xenos, you could lose relative image quality. You'll lose the free AA for example. But not using the special features isn't going to change the number of vertices you can transform, light, texture, shader and render. Basic graphics works the same. Also, the SDKs had a predicated tiling emulation too IIRC, which we're told isn't that difficulat to implement as long as it you start with it in mind, so devs could have written their Xenos friendly engine on the earlier SDKs and ported it over. I find it surprising therefore that PGR uses a downsized frambuffer to fit into AA and they didn't develop a tiled renderer; there doesn't appear to be an SDK limitation that prevented this.
Comparing Xenos to GS, GS was a totally alien device to what people were used to. You had to think and write differently to use it. It offered a steep learning curve and that's why first gen games looked pants. RSX is offering a traditional interface and so first gen titles should get as much out of it as their PC counterparts. Likewise Xenos offers a traditional interface (from what I know) and you can get as much from it from a DX engine as you can get from a 'similar' PC part. Not using predicated tiling and MEMEXPORT isn't going to quarter the vertex tranform rate or pixel shading power. The basics of graphics rendering will be as good whether the special sauces are applied or not. And in the example of rendering a tree, Xenos isn't at a programmability disadvantage to draw a load of branches and leaves vs. RSX. If this talk of a tree looking better on PS3 vs. XB360 is true, it's not due to the GPUs. Both are very capable. I'll even say both CPU's are very capable, and the reason the PS3 example looked better was just it was better written. Take a look at Oblivion and you'll see plenty of moving trees