amd64 optimized gcc?

[Nicolas Blais]

I am developping a software that follows a random()-dependant algorithm which 
is extremely cpu intensif. 
I decided to run on different platforms to see how it performed based on cpu 
and os (in a way of benchmarking) and I'm surprised by the numbers:

Reference times for benchmark (5e+07 run of the algorithm):

(FreeBSD/i386)  Venice (S939, 512K L2 cache) Athlon64 3000 overclocked @ 2655 
Mhz : 78.3072 s (638511 r/s)
                Note: Cool 'n' Quiet! Disabled in BIOS.
		Note: 1 G RAM

(FreeBSD/amd64)  Venice (S939, 512K L2 cache) Athlon64 3000 overclocked @ 2655 
Mhz : 71.2521 s (701732 r/s)
                Note: Cool 'n' Quiet! Disabled in BIOS.
		Note: 1 G RAM

(Knoppix/i386)  Clawhammer (S747, 1MB L2 cache) Athlon64 3200 @ 2000 Mhz : 
133.858 s (373325 r/s)
                Note: Compaq R3240CA Laptop, Cool 'n' Quiet! forced by BIOS.
		Note: 512 M RAM

(FreeBSD/amd64) Clawhammer (S747, 1MB L2 cache) Athlon64 3200 @ 2000 Mhz : 
47.2754 s (1057630 r/s)
                Note: Compaq R3240CA Laptop, Cool 'n' Quiet! forced by BIOS.
                sysctl hw.acpi.cpu.px_control=-1
		Note: 512 M RAM

(FreeBSD/i386)  Pentium II @ 233 Mhz : 538.136 s (92913.3 r/s)
		Note: 192 M RAM

Not surprising is the Pentium II :).  What is surprising is that amd64 FreeBSD 
seems to execute code faster than i386 FreeBSD, so I'm wondering if gcc 
(amd64) really optimizes code for the cpu. If it is, I would probably move my 
httpd server to amd64...

Also, maybe less surprising is that Knoppix sucks running the algorithm for 
some reason and that L2 cache really is a big factor (my Laptop outperforms 
my heavily overclocked box).

Any comments?
-- 
FreeBSD 6.0-CURRENT #2: Sun May 22 11:29:47 EDT 2005     
nicblais at clk01a:/usr/obj/usr/src/sys/CLK01A 
PGP? : http://66.130.198.54:8081/security/nb_root.asc
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