[ltp] How much performance improvement going from 32-bit to 64-bit linux?

Yves-Alexis Perez linux-thinkpad@linux-thinkpad.org
Fri, 18 Sep 2009 12:12:02 +0200


Joerg Bruehe a écrit :
> Running 64 bit applications means all pointers are twice the size, so
> storage demands increase. I expect performance to suffer.
> The gain would only come if your applications really use so much memory
> that the 4 GB address space limit matters: large caches come to mind,
> like in databases, maybe video editing, other memory-intensive stuff.
> 
> With typical home or office use, I don't expect the 4 GB limit to matter
> for an individual application  -  large servers would be a different thing.

I the general case, yes, 64 bits means bigger pointers and storage
increase. But in the i386 -> x86_64 switch, that means passing from 8 to
16 general registers (which are bigger too)


-- 
Yves-Alexis