Re: 32 bit application on 64 bit os

SaranJothy wrote:
hi,

Because you're waiting for the very same hard disk that always works
at the very same slow speed.

i m reading and writing from the ramdisk.(using ram as a partition) not
using harddisk
so what can be difference?


Because you're waiting for the very same hard disk that always works
at the very same slow speed.


As per my little knowledge, Since in 32 bit machine (read/write)
process 32 bits of data in 1 clock cycle and in 64 bit
machine(read/wrie) process 64 bits of data in 1 clock cycle, there
should be a differnce in performance.( half the time). Am i correct??

You're wrong. It would be true if your 64-bit machine could process 2 32-bit values in parallel (which it often can, but then it can also process two 64-bit values in parallel).
Your 32-bit application processes one 32-bit entity per clock cycle (if we stay with this assumption), while your 64-bit application processes one 64-bit entity per clock cycle, where, one could say, 32 bits are wasted compared with the 32-bit application.
In any case, both process one entity per cycle.

If i want to utilize the power of 64 bit machine should i need to use
lots of 64 bit data type?

No, you would just extend the range of values. If you do not extend the range, see above. Ie it doesn't matter whether you add 0x12345678 to 0x87654321 or add 0x0000000012345678 to 0x0000000087654321.
64-bits come into full power if you have huge data structures or if you use memory mapped files a lot (imaging mmap-ing and processing a 4.7GB DVD image) or if you use lots of extremely huge values (long longs, e.g. the number of security bugs in W******s ;-).

let say if my application uses only characters datatype will it make
any difference or not?
say example reading and writng strings with RAM?

Most likely there will be little difference. There may be some difference e.g. in copying operations where 8 characters rather than 4 characters can be processed in one go.

Josef
--
Josef Möllers (Pinguinpfleger bei FSC)
If failure had no penalty success would not be a prize
-- T. Pratchett

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