Matt wrote: > I am upgrading a server that mounts in a rack. Its going on the > cheapest socket 775 CPU I can buy and in a 1u rack case. All its for > is keeping some log files and doing some simple MYSQL/PHP database > stuff. Not a work horse at all. Anyway, is it better to go 64bit or > 32bit for the CentOS 5.x install? I do not see needing huge amounts > of RAM or anything like that on this box. Would the 32bit version be > more tried, proven and stable? Stick to 32-bit unless there's an explicit need to go to 64-bit. 64-bit requires a lot more memory. 64-bit should be perfectly fine from a stability perspective but it's too much of a memory hog. Sample memory usage(32-bit): root 4059 0.0 0.2 11616 4532 ? S 04:02 0:01 /usr/sbin/snmpd -Lsd -Lf /dev/null -p /var/run/snmpd.pid -a root 10721 0.0 0.0 4516 1048 ? Ss Jun23 0:00 /usr/sbin/sshd postfix 20038 0.0 0.0 5560 1720 ? S 09:49 0:00 pickup -l -t fifo -u root 22302 0.0 0.1 7488 2480 ? Ss 11:21 0:00 sshd: root at pts/1 root 29154 0.0 0.0 6780 1692 ? Ss Jul30 0:01 /usr/libexec/postfix/master postfix 29158 0.0 0.0 6024 1868 ? S Jul30 0:00 qmgr -l -t fifo -u 64-bit: root 2792 0.0 0.0 88028 5700 ? S 04:02 0:02 /usr/sbin/snmpd -Lsd -Lf /dev/null -p /var/run/snmpd.pid -a root 22946 0.0 0.0 26224 2108 ? Ss Jul30 0:00 /usr/libexec/postfix/master postfix 22950 0.0 0.0 26336 2200 ? S Jul30 0:00 qmgr -l -t fifo -u root 26090 0.0 0.0 37100 2656 ? Ss 11:23 0:00 sshd: root at pts/0 postfix 30228 0.0 0.0 26284 2104 ? S 10:34 0:00 pickup -l -t fifo -u root 31734 0.0 0.0 21924 1180 ? Ss Jun23 0:00 /usr/sbin/sshd --- snmpd - from 11M to 88M postfix/master - from 6.7M to 26M sshd - from 7.4M to 37M postfix/pickup - from 5.5M to 26M Unless you have gobs of ram and don't care about the extra memory usage. For me unless I have processes that need more than 2GB per process, or overall memory on the system is higher than 8GB I stick to a 32-bit OS. If I have more than 8GB, that implies that I actually plan to use more than 8GB at which point I believe 64-bit starts making more sense as PAE can get pretty expensive for memory intensive things. The above 64-bit system has 16G, the 32-bit system above has 2G. nate