On 8/17/2010 5:09 AM, Rayson Ho wrote:
On Tue, Aug 17, 2010 at 7:59 AM, Johan Hartzenberg wrote:
If however your application use the features of 64-bit programs then the
advantages can be more than these overheads. For the most part this means
programs that require access to more than 4 GB of
On Tue, Aug 17, 2010 at 7:59 AM, Johan Hartzenberg wrote:
> If however your application use the features of 64-bit programs then the
> advantages can be more than these overheads. For the most part this means
> programs that require access to more than 4 GB of data in RAM.
A lot of applications
Further to what Jim mentioned below, 64-bit-ness does not imply faster
execution. On the contrary it means each instruction, data address and data
access requires more bits to move across the bus, compared to the 32-bit
version, to do the same work. For example to sort a list of words (text)
the
Typically such performance disparities are due to
changes in the memory footprint with the 64-bit code,
and resulting cache miss rates being higher with the
64-bit code than the 32-bit code.
You need to use the Studio tools to profile the code,
and/or cputrack to measure cache hit rates.
Thanks,
