[lsb-discuss] Definitive use of /etc/* files for system-wide application data maintenance

[Bruce Dubbs]

Christopher Yeoh wrote:

> On some architectures there are performance reasons for using 32 bit
> binaries instead of 64 bit ones. On PowerPC for example if you don't
> actually need 64 bit then a 32 bit binary can be smaller (less pressure
> on the cache), pointers can be a bit faster etc.
> 
> So it can be quite appropriate to have a mixed 32/64 bit environment.

I do not have comprehensive data on a lot of architectures, but I do 
have one reasonably important data point.  On an Intel Core2Duo, I built 
Linux From Scratch from an automated process in both 32-bit and 64-bit 
modes.  The results were:

Architecture Build Time     Build Size
32-bit       198.5 minutes  648 MB
64-bit       190.6 minutes  709 MB

As you can see, the 64-bit build is only 4% faster and is 9% larger than 
the 32-bit build.  The real advantage of 64-bit is when physical memory 
exceeds 4G or when the user is manipulating data greater than 4G.

The real issue here is subjective.  Most people who have 64-bit capable 
hardware would not want to run a 32-bit system even though there would 
be no discernible difference.

   -- Bruce