32bit Vs 64bit OS
alan at lxorguk.ukuu.org.uk
Fri Jun 18 22:08:41 UTC 2010
O> Agreed. First, the 64-bit OS itself should be a bit faster than a 32-bit
> OS on the same platform. But, in my experience with 64-bit going back 16
> years there are some applications that will run faster if built for
> 32-bit and some will run faster if built for 64-bit. There are some
> tradeoffs. The sizes of libraries and applications will be larger in
> 64-bit. You will need both 64-bit and 32-bit libraries if you want to
> run 32-bit apps.
The x86 case is a bit different to the others (indeed for example sparc64
user space is mostly faster 32bit)
On x86 the CPU has a real shortage of registers. The 64bit mode changes
this somewhat which means its not a simple 64bit extend but also other
performance improving features that become available.
More information about the users