In article <37E42D15.F0B1DDEF@pacbell.net> , lyonstb <lyo### [at] pacbellnet>
wrote:
> yes I understand that it is single
> threaded but don't you think that number
> crunchin code (like povray) would run
> faster on a computer that was built for
> utra fast number crunching??? or has
> povray been so influenced by the intel
> world that the code/algorithm has a "speed
> limit"?

Well, no, it is not "influenced by the intel". However, the whole
architecture runs best on memory based systems as storing vectors in arrays
can't be optimized into registers on load/store based architectures by
compilers available today.
Now the Cray (at least the model I know which is a Cray-X MP) actually have
a very fast processor <=> memory interface. So that should not hurt you.
But notice that the i.e. the Cray-X MP will give you only about 120 MIPS and
230 MFLOPS which is not much compared with modern CISC or RISC CPUs.
I assume you know the performance to expect from the YMP Cray and if what
you currently get is not what you expect, you will need to tune the compiler
settings (and make sure you link with the fastest memory management library
you can get).  If that doesn't give a major speedup it is either a bad
compiler or you are in fact at the peak of the system speed for this
particular application (POV-Ray).   Good luck!


     Thorsten


____________________________________________________
Thorsten Froehlich, Duisburg, Germany

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