[extropy-chat] Using Graphic controllers

[Paul Bridger]

Dan Clemmensen wrote:

> Another interesting point: From the point of view of raw computational 
> power, the sum of all the 3D graphics cards in the world probably 
> exceeds the sum of all CPUs in the world. Sure, the graphics cards are 
> special-purpose, but what if you had the resources to carefully create 
> algorithms that are well suited to graphics cards? basically, this 
> requires that you map your problem onto the space that is easily 
> addressed by graphics cards. The extremely obvious problem is graphics 
> rendering (DUH!) This has actually been done: you can use graphics 
> cards to run the POV-RAY backend. When you do this, a few (10?) 
> machines with graphics cards can render scenes that would otherwise 
> take hundreds of high-end CPUs.

The major problem with the unused GPU (Graphics Processing Unit) power 
is that most of it is primitive fixed-function hardware. Newer hardware 
is increasingly general purpose (I'm talking about vertex/pixel 
programs). My guess is that the number of problems that can be mapped 
into the space of fixed-function hardware is fairly limited. However, 
programmable hardware raises incredible new possibilities. The only 
thing holding back photorealistic rendering in realtime today is 
programmer skill.
A large restriction on the computation you farm off to your unused GPU 
resource is that it must be able to be computed in parallel. This is the 
reason that modern graphics cards have higher complexity than modern 
CPUS -- graphics processing is an inherently parallel process and the 
structure of the cards mirrors this. Modern graphics cards run >500MHz 
(but have high parallelism) whereas modern CPUs are upwards of 3GHz.