[CentOS] OT: Thunderbird2 for 64 bits

Wed Feb 27 21:52:57 UTC 2008
nate <centos at linuxpowered.net>

Simon Jolle sjolle wrote:

>> In 64-bit mode I wouldn't be surprised if the same usage would
>> come out to 500MB+ memory usage.
>
> Again why?

Because 64-bit apps in general use more memory


SSH 64-bit:
root      4193  0.0  0.0 21932 1272 ?        Ss   Jan29   1:00 /usr/sbin/sshd

SSH 32-bit:
root     19725  0.0  0.0   4392   276 ?        Ss    2007   7:52 /usr/sbin/sshd

500%+ more memory

SNMPD 64-bit:
root      4146  0.0  0.0 88316 5952 ?        S    Jan29   2:58
/usr/sbin/snmpd -Lsd -Lf /dev/null -p /var/run/snmpd.pid -a

SNMPD 32-bit:
root     19928  0.0  0.1  14436  2032 ?        S     2007  42:07
/usr/sbin/snmpd -Lsd -Lf /dev/null -p /var/run/snmpd -a

600%+ more memory

Apache 64-bit:
apache   24540  0.3  0.2 108212 13700 ?      S    11:17   0:28 /usr/sbin/httpd

Apache 32-bit(same module config):
apache   28602  0.0  0.6  16136  6884 ?        S    08:19   0:00
/usr/sbin/httpd

600%+ more memory

List goes on..

I don't mean to imply that it's certain to use 2-3x more memory, but
in my experience it appears that 64-bit apps use much more memory
than 32-bit. I've read they can use up to 2x more memory, but clearly
in some cases it can go way beyond 2x.

It's just not worth it for most things. I tried migrating a web server
that runs Ruby on Rails/FastCGI from 32-bit to 64-bit and experienced
a 300% increase in memory utilization and about a 75% reduction in
performance. (before that my goal was to try to make everything
64-bit to make it easier to manage).

nate