POV-Ray : Newsgroups : povray.pov4.discussion.general : GPU usage : Re: GPU usage Server Time
22 Dec 2024 00:19:39 EST (-0500)
  Re: GPU usage  
From: Chambers
Date: 7 Jan 2009 03:50:49
Message: <5412C33CFC874C64AD0AFF80C11C2654@HomePC>
(Sorry it took me so long to respond, our internet connection was down
for a while).

While the OpenCL spec is very exciting for the GPGPU effort, it will not
help renderers such as POV-Ray.  Ultimately, they still come down to a
SIMD design: specify one instruction (or one set of instructions), and
run it on multiple sets of data.

In practice, this means that anything with a high degree of branching
(ie POV-Ray) won't benefit nearly as much.

Of course, the new GPUs are more capable than ever, and they do offer
double precision floating point, so it may at one point be possible for
limited aspects of the renderer.  However, bear in mind that even
something as inherently SIMD as video encoding, using a high end GPU
from NVidia (the GeForce 260) was actually *slower* than a stock Core 2
Duo from Intel (1).  Something with as much branching as POV-Ray will
perform even worse.

So, there's new hope for the future, but it's still a *distant* future.

(1)
http://xtreview.com/addcomment-id-6872-view-CUDA-video-performance-using
-TMPGEnc-4.0-Xpress.html

...Ben Chambers
www.pacificwebguy.com

The plural of anecdote is not data  --Elbows


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