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Re: NetBSD speed curiosities



On 16/04/14 3:27 PM, Dave McGuire wrote:
On 04/16/2014 03:03 PM, John Klos wrote:
I'm still puzzled by one thing that perhaps someone could explain. The
Dhrystone benchmark from pkgsrc should be pretty consistent due to its
simplicity. However, my 4000/30 (VLC) with NetBSD 6, which by many
sources is supposed to be 5 VUPs or so, only reports 2109 runs per
second, which is only about 1.2 times faster than the runs per second of
an 11/780.

A 4000/60, which is supposed to be about 12 VUPs, gives 16305 runs/sec,
which is about 9.2 times faster than an 11/780.

Maybe it's me, but these ratios seem well within the fuzziness I'd expect given all the variables (including, as Dave sagely noted, cache). A VUP is an archetypically vague unit.

--T


Why is this? Is there some issue which makes code too large to run
inside of the CVAX SOC's 6k of cache? Is anyone running NetBSD 1.5 or
another old version who could get some more numbers?

   I would immediately suspect caching issues here.  Have you looked at
the assembler output?

                -Dave




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