[arch-general] A question about Arch Sixty Four

[Gary Wright]

2010/5/24 Frédéric Perrin <frederic.perrin at resel.fr>:

> On a 64 bit machine, in « char *p; », p will use 64 bits (8 bytes),
> instead of 4 bytes in a 32 bits machine [I'm talking about p, not about
> *p which doesn't look like it exists]. Gary Wright seems to be saying
> that the impact is negligible. Nicky726 seems to be saying that there
> is a difference of up to 80%. I am surprised by such a claim, but there
> seems to be anecdotes on Google of people seeing the same thing. As I
> don't have a 64 bits machine, I can't test for myself.
> --
> Fred

Well, heres something vaguely empirical.  Just downloaded the two
latest netinstall medias and threw them on a usb stick.  I ran
precisely four commands after logging in as root on each netinstall
arch:

1) mkdir /mnt/tmp
2) mount /dev/sda3 /mnt/tmp  #my home partition
3) uname -a >> /mnt/tmp/gary/memcomp
4) free -m >> /mnt/tmp/gary/memcomp

results to be seen here:
http://aur.pastebin.com/YwTJA6cR

short story:  ~29 MB more used on x86_64... or about 30 percent.

But when installing a whole system, many more variables come into
play.  It might have just been my dumb luck that ram usage ended up
within 1-2 mb of eachother.

Gary