🚀 go-pugleaf

In comp.dsp Michael.Malak@halluc.com (Michael Malak) asks:

Michael> Does anyone have any information about how fast the i860 can do an FFT,
Michael> either theoretical or measured?

and alans@ll.mit.edu (Alan Stein) responds:

Alan>In the 860 bible (i860 Microprocessor Architecture by Neil Margulis),
Alan>the author codes an FFT which achieves 57/80 MFlops. This is not really 
Alan>what the beast is designed to do, IMHO. Seems I'm always writing 3 
Alan>different versions of the same routine - one for extremely short vectors
Alan>(throw everything in registers), one for medium-sized "if it all fits 
Alan>in cache" vectors, and one for long vectors that use pipelined memory
Alan>loads, bypassing the cache because they would just thrash. I suspect 
Alan>I'd wind up doing much the same if I were coding an FFT, which
Alan>I haven't [as yet] had to do.

Malak was interested in comparing the i860 FFT performance to other 
commercially available DSPs. My question is: what is the FFT performance of
the family of DEC alpha micros (theoretical, simulated, or measured ???)?
I would be interested in knowing not only MFlops, but also FFT algorithm,
transform size(s), optimum execution times, and any stipulations (as
described by Alan above) associated with the benchmarks.

     Thanks in advance.

     
Gary Shiflett
Applied Physics Laboratory
Johns Hopkins University
gary_shiflett@jhuapl.edu
(301)953-6000x8141