What OS is better for a dedicated server
 

On a Dual Processor Dual Core Opteron 2214HE dedicated server running mainly mysql+apache what OS wold be better between Fedora Core 6 i386 and Fedora Core 6 x86_64 ?

always been a CentOS addict :S

If you are running 64bits apps, then it's a better thing to have a 64bit os, but you can run into trouble with unsupported software and some software will only run in 32 bits. You should check with your admin.

recommend CentOS . . .also has 64 bit if that is important

if your machine has a 64-bit cpu, get the 64 bit version of the OS. It doesn't change things much for many applications, but it's worthwhile for the few that benefit from the difference.

what would be the benefits of 64-bit cpu over a 32 bit cpu?

A 64-bit OS would run faster.

64Bit OS primary advantage is being able to address more RAM natively.

x86 or i386 architecture can only address 3.2GB natively, afterwards it uses PAE ( physical address extension ) to map the rest

So if you are using 4+GB of RAM then go with 64Bit -- otherwise it wont make much of a difference as most server tasks like Apache/MySQL wont be heavily influenced by 32vs64bit.

As a standard rule we've switched to installing 64bit OS's whenever possible as its impossible to upgrade from 1 to the other without a format.

The only downside is its a bit tricky to get a few apps running in 64bit OS - the upside its honestly a simple process - get a 32bit machine, compile it there statically and copy it over :)

But when you have only 1 server - it can be complicated :)

FreeBSD IMO and from my experience

twice as many bits

Windows 3.11

FreeBSD fuck fedora

Debian is very simply to configure.
apt-get install debian :D

The only real answer to this question is FreeBSD Baby, nothing else even comes close.:2 cents::thumbsup

As mentioned above, I'd stay away from Fedora. It's not what you want for a server.

If you're going to go Linux, I'd recommend CentOS. It's basically Red Hat Enterprise without the price tag.