[mdlug] Time to jump to 64-bit?

[Michael Corral]

2009-10-29, Monsieur Ingles, Raymond a ecrit:
> I understand that the 64-bit instruction set has extra registers and
> such, which can provide a boost of a few percentage points in some
> tasks. But I've heard that there's problems with Flash support, and I
> use Wine and some emulator stuff to run older Windows games. Overall, I
> don't know if the benefits of 64-bit would outweigh the drawbacks in my
> case.

I've heard that it makes a noticeable difference for video recording
and editing. In my experience it helped speed up compiling LaTeX files
and running some operations in R, i.e. mathematically intensive tasks.
For example, try printing all 12,978,189 digits of the 46th Mersenne
prime (2^43112609 - 1) to a file using the GMP library; it's way faster
in 64-bit than in 32-bit (see code at the end of this message).

As others have said, you won't notice any difference for most things.
And if you have the disk space then installing 32-bit libs won't be
an issue. Personally, I tried 64-bit for a while then went back to
32-bit, since I didn't feel like installing extra libs just to make
32-bit stuff work. The advantages of 64-bit weren't great enough.

Michael

-------------------------------------------------------
/* mersenne.c */
#include <stdio.h>
#include <stdlib.h>
#include <gmp.h>
int main(int argc, char *argv[]) {
    char *endptr;
    unsigned long int p = strtoul(argv[1],&endptr,10);
    mpz_t M, powerof2, one, two;
    mpz_init(M); mpz_init(powerof2);
    mpz_init_set_str(one,"1",10);
    mpz_init_set_str(two,"2",10);
    mpz_pow_ui(powerof2,two,p);
    mpz_sub(M,powerof2,one);
    gmp_printf("%Zd",M);
    return 0;
}
------------------------------------------
$ gcc -o mersenne mersenne.c -lgmp
$ time ./mersenne 43112609 > M46

real    0m17.226s
user    0m16.874s
sys     0m0.163s