On Sun, Mar 23, 2008 at 6:41 AM, Francesc Altet <
faltet@carabos.com> wrote:
A Sunday 23 March 2008, Charles R Harris escrigué:
> gcc --version: gcc (GCC) 4.1.2 20070925 (Red Hat 4.1.2-33)
> cpu: Intel(R) Core(TM)2 CPU 6600 @ 2.40GHz
>
> Problem size Simple Intrin
> Inline
> 100 0.0002ms (100.0%) 0.0001ms ( 68.7%)
> 0.0001ms ( 74.8%)
> 1000 0.0015ms (100.0%) 0.0011ms ( 72.0%)
> 0.0012ms ( 80.4%)
> 10000 0.0154ms (100.0%) 0.0111ms ( 72.1%)
> 0.0122ms ( 79.1%)
> 100000 0.1081ms (100.0%) 0.0759ms ( 70.2%)
> 0.0811ms ( 75.0%)
> 1000000 2.7778ms (100.0%) 2.8172ms (101.4%)
> 2.7929ms ( 100.5%)
> 10000000 28.1577ms (100.0%) 28.7332ms (102.0%)
> 28.4669ms ( 101.1%)
I'm mystified about your machine requiring just 28s for completing the
10 million test, and most of the other, similar processors (some faster
than yours), in this thread falls pretty far from your figure. What
sort of memory subsystem are you using?
Yeah, I noticed that ;) The cpu is an E6600, which was the low end of the performance core duo processors before the recent Intel releases, the north bridge (memory controller) is a P35, and the memory is DDR2 running at 800 MHz with 4-4-4-12 timing. The only things I tweaked were the memory voltage and timings. Raising the memory speed from 667 to 800 made a noticeable difference in my perception of speed, which is remarkable in itself. The motherboard was cheap, it goes for $70 these days.
I've seen folks overclocking the E6600 up to 3.8 GHz and over 3GHz is common. Sometimes it's almost tempting...
Chuck