Newbie question about text encoding

[Dave Angel]

On 02/26/2015 08:05 PM, Steven D'Aprano wrote:
> Rustom Mody wrote:
>

>
>> eg consider the case of 32 vs 64 bit executables.
>> The 64 bit executable is generally larger than the 32 bit one
>> Now consider the case of a machine that has say 2GB RAM and a 64-bit
>> processor. You could -- I think -- make a reasonable case that all those
>> all-zero hi-address-words are 'waste'.
>
> Sure. The whole point of 64-bit processors is to enable the use of more than
> 2GB of RAM. One might as well say that using 32-bit processors is wasteful
> if you only have 64K of memory. Yes it is, but the only things which use
> 16-bit or 8-bit processors these days are embedded devices.

But the 2gig means electrical address lines out of the CPU are wasted, 
not address space.  A 64 bit processor and 64bit OS means you can have 
more than 4gig in a process space, even if over half of it has to be in 
the swap file.  Linear versus physical makes a big difference.

(Although I believe Seymour Cray was quoted as saying that virtual 
memory is a crock, because "you can't fake what you ain't got.")




-- 
DaveA