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Ocaml sums the harmonic series -- four ways, four benchmarks: floating point performance
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Date: -- (:)
From: Michal Moskal <michal.moskal@g...>
Subject: Re: [Caml-list] Ocaml sums the harmonic series -- four ways, four benchmarks: floating point performance
On Sat, 15 Jan 2005 12:55:19 +0100, Xavier Leroy <Xavier.Leroy@inria.fr> wrote:
> As others have mentioned, this strongly depends on the processor
> instruction set and even on the processor model.  My own benchmarks
> (with your Caml code) give the following results:
> 
> PPC G4 (Cube)   1 < 2 < 3 < 4 < 5   speed ratio = 1.5
> Xeon 2.8        3 < 4 < 1 = 2 < 5   speed ratio = 1.02
> Pentium 4 2.0   3 < 1 < 2 < 4 < 5   speed ratio = 1.2
> Athlon XP 1.4   4 < 5 < 3 < 1 < 2   speed ratio = 2.2

I tested it on Athlon 64 3000+ using both 32bit and 64bit compilers,
the results:

32bit: 4 = 5 < 3 < 1 = 2, speed ratio 2.2
64bit: 3 < 1 = 2 = 4 < 5, speed ratio 1.15

Difference between 64 and 32 bit version (best cases) is 1.30 (64 is faster).

All tests were performed using ocaml 3.07.

> The Athlon figures are *very* surprising.  It could be the case that
> this benchmark falls into a quirk of that (otherwise excellent :-)
> processor.

So I guess in 32 bit mode it remains the same on newer athlons.

-- 
: Michal Moskal :: http://nemerle.org/~malekith/ :: GCS !tv h e>+++ b++
: No, I will *not* fix your computer............ :: UL++++$ C++ E--- a?