Larry Fontaine wrote:

> The problem with multiple processors is that n number of x-MHz
> processors aren't as fast as 1 x*n-MHz processor. I.E. they don't run at
> full capacity. Two processors is a huge performance gain, four is too,
> eight is ok, sixteen gets a little, thirty-two or more would be a huge
> waste of money. The thing is, the graph of performance vs. processors
> starts to level off after so many, because multi-processor machines
> waste a lot of time with processor communication. With 1024 processors,
> each processor has to "talk" to 1023 others, and there is minimal gain
> over 512 or 256. You may could instead use 1024 seperate motherboards
> each running a copy of POV. That would be plausible, because you would
> only need the video card, monitor, CD, etc on the main system, which is
> half the cost of a computer. And with the POV ability to render a
> selected section of the picture, you could indeed have real-time
> rendering. However, 2000000 PII's with motherboards would cost a good
> billion and a half dollars, which is probably less than multiple Cray
> XMPs though I really have no idea what those cost.

	Agreed on all points. But I am not talking parallel in the sense
of distributed. Parallel in the sense of working on the same
project at the same time. These do not have to talk to each other
as they each would work on their own pixel. X at a time instead
of one at a time. 

	Clearly POV would be in ROM and enough RAM to hold the parsing
results  and not much more needed. Parsed input can take a few
seconds and the output is 3 bytes per pixel = cheapest ethernet
card you can find. This should be well under $300/board in
quantity even with off the shelf boards. $300,000 in hardware,
rented out at $100 to $1000 per hour? And the small boards for
embedding have been around for years. 

	Of course the "millions" of processors were just to set the
stage for small numbers of processors against creation time.
Perhaps how close we are to the holy grail of not having to pay
actors for movies.

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