🚀 go-pugleaf

In article <713099311.0@halluc.com>, Michael.Malak@halluc.com (Michael Malak) writes:
>I found the recent article in the August/September issue of Circuit Cellar Ink
>about DSPs vs. RISC very interesting.  In it the i860 is benchmarked as being
>the fastest at 96-tap FIR filtering.  It was compared against the Am29050, the
>C30, the 56001, the 96000, and a few others.  But that's as far as the article
>went -- it did not compare performance for doing FFTs.
>
>Does anyone have any information about how fast the i860 can do an FFT, either
>theoretical or measured?  I'm especially interested in how it compares against
>the C30, the 96000 and the 56001.  Because since there don't seem to be any 386
>or 486 motherboards out there with DSPs on them, the one from Happauge with the
>i860 on it might be worth a look.
>

If the following two conditions are met:

	1. All your data occupies less than 8 kbytes (such that all data
	   is in the cache or in registers)
	2. Your algorithm is such that it can be implemented in i860
	   pipelined mode (which is awkward to program)

then the i860 is a winner. Otherwise, it's a loser (if you compare with
dedicated DSP's). Non-pipelined mode is 3-4 cycles per instruction, memory
bandwidth is one access per two cycles, if my memory serves me right.

-- 
***** hlj@hal.nta.no (Harald Ljo"en) expressing his private opinions ******