[rescue] Cray J90s

rescue at sunhelp.org rescue at sunhelp.org
Tue Jun 12 18:39:57 CDT 2001


mcguire at neurotica.com writes:

>  Vector processors, on the other hand, operate on vectors as atomic
>values.  They can perform the same operation on whole lists of numbers
>(vectors) in one operation...one vector instruction.

Which is not to say one clock cycle or anything close. In fact,
isn't there usually just one or two instruction units that are
processing each element of that array? So - it saves you the 
overhead of keeping track of the loop, and optimizes utilization
of the pipeline. It doesn't actually calculate all the entries
simultaneously.

And for a bizarre comparison: couldn't the Cyber 205  and its ETA
descendants do memory-to-memory vector instructions on 64K
element arrays?

-- david fischer -- dave at cca.org -- www.cca.org -- Cthulhu told me to. --



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