[Nauty] Re: Anyone running nauty on AMD64?

[Gordon Royle]

On 30/08/2005, at 11:03 PM, <keith.briggs at bt.com> wrote:

> Gordon Royle wrote:
>
>> Is anyone compiling and running nauty/geng using gcc in 64-bit  
>> mode on an AMD64 chip?
>>
>   I ignored this and compiled it anyway.
>
> 2. "geng -u -c 10" (about 12M graphs) takes 12s on the AMD 3400+  
> cpu, about twice as fast as my
>      Pentium 4 2GHz machine.



Thanks for the info... I guess that for geng on small graphs, there  
is no speed-up due to the 64-bit word length, so probably most of  
this speedup can be attributed just to the increased clock speed, and  
probably better peripherals..

I wonder if there is a more significant speed-up on bigger graphs,  
where the 64-bit word length would mean fewer operations need be done..

Gordon