

800TFLOPS Multicore IC for Realtime Ray Tracing - profquail
http://techon.nikkeibp.co.jp/article/HONSHI/20090629/172373/

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Retric
There must be a mistake somewhere. 800TFLOPS / 750MHz = 1 million FLOPS /
cycle. As there are 130 million gates you would need to do 1 FLOPS with 130
gates. At 6Ghz you still only have 1040gates which is not going to cut it for
32 bit math.

Edit, Ok,
[http://techon.nikkeibp.co.jp/article/HONSHI/20090629/172373/...](http://techon.nikkeibp.co.jp/article/HONSHI/20090629/172373/fig1.jpg)
has 88TFLOPS _equivalent_ per IC which might be possible if equivalent is
loosely defined. And with 9 of those you might hit 900TFLOP's _equivalent_.

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akamaka
Thanks for posting, this is very interesting. I wish they included more
details.

The realm of realtime computer graphics has been totally dominated by the
SGI+Renderman line of thinking, and realtime raytracing has only made
occassional appearances in demos or academic research (and possibly the pipe
dreams of Intel executives wishing for a disruptive technology to make up for
their weakness in graphics).

It's fascinating that they're willing to build custom chips for this purpose.
Are Toyota's needs simply so advanced that they couldn't do anything else? Or
will this be another Cell processor type project, a chip launched with high
hopes and only one major customer?

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nvoorhies
Automotive applications are different in that they're inordinately concerned
with the appearance of reflections, especially in areas such as the appearance
of the headlights. This makes non-raytraced approaches substantially less
valuable in the design process. They really want to know what the shiny bits
will look like ahead of time.

Raytracing still suffers form the performance implications of incoherent
memory accesses patterns for non-primary rays, but when you want physically
correct reflections and shadowing to fall out of the rendering architecture
naturally, an implementation of ray tracing in hardware starts to look like a
pretty spiffy idea.

Are there other fields that require physically correct models for reflections,
etc? None spring to mind for me right away.

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profquail
Designing lenses and mirrors for things like telescopes and lasers, I'd
imagine.

Also, a slight adaptation could be good for radiation and electromagnetic
research (e.g. how well a material blocks beta radiation, etc.)

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capsid
It's amazing that these chips aren't sacrificing precision for performance,
operating on Bezier curves.

While we're on the subject of realtime raytracing, does anyone have insight
about the polygons vs voxels debate for normal (i.e. desktop apps, games)
programmers?

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TrevorJ
The last time I heard anything about this, the bottleneck on the voxel side
was problems with surface texturing. That was some time ago though, and I'm
not sure what progress has been made on that front.

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th0ma5
It seems having followed this over the last several months that many argue
that ray tracing is really great, and obviously the way the world works, but
scene graphs and filters and such with existing matrix transformations like in
DirectX and OpenGL are always going to outperform raytracing because it is
just inherently simpler. However I don't do too much development in this area,
so I would welcome any other perspective!

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lutorm
I don't think it's a matter of performance, but of realism. If you want
realistic calculations, you must go to a ray tracing algorithm, there's no
substitute.

If you don't need 100% realism, though, you can probably make things look 99%
as good with "fake" effects, with better performance.

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TrevorJ
Correct. The "fake" effects have limitations and you can break them under
certain circumstances, so raytracing is always a good choice when you aren't
sure how the materials will be used and under what conditions they will be
rendered.

