Cray divide speed

[John D. McCalpin]

Does anyone have the figures handy for the peak speed of the Cray
X/MP, the Cray Y/MP, and the Cray 2 for vector divide operations?

I know that Cray uses an approximate reciprocal scheme, but I need to
know how many cycles per result are required for a plain vector
divide, i.e.

	DO 100 I=1,N
	    A(I) = B(I)/C(I)
  100	CONTINUE

On the Cyber 205 and ETA-10, the number is 6 cycles per element, and I
am trying to figure out if that is a representative number for vector
machines. I am using this information to modify the work estimates for
various implicit and explicit finite-difference schemes used in fluid
dynamics.
--
John D. McCalpin - mccalpin at masig1.ocean.fsu.edu
		   mccalpin at scri1.scri.fsu.edu
		   mccalpin at delocn.udel.edu