> I am interested in buying my first Linux box. However, this is needs to
> be a decent server, helping me to migrate web applications to Linux,
> notably J2EE with relational and xml databases.
> As such, I am already eyeing motherboards holding Dual Xeon P4 2 ghz
> chips. This is where I am very concerned about Linux. I don't know much
> about how two CPUs work together, and what role the OS and the apps have
> to play in optimizing their use. My worst fear is getting everything up
> and running, only to find that the system is only using one CPU.
Well, if you are going to tweak performance, you will probably rebuild
your kernel. So you rebuild it for SMP support. Piece of cake. I've
been running SMP linux since p5/166 days, with no problem at all. I
currently have a dual pII/350 server, a dual PII/450 server, and a daul
PIII/550 workstation. The two servers run highly customized versions of
redhat; the workstation is pretty much a stock RH 7.2 install.
> If the apps play a role, then this is probably going to come down to the
> Java Virtual Machine and database engines (e.g., MySQL).
Well, if apps are multi-threaded, they will take advantage of SMP. If
not, they will not. Simple as that. There still are advantages to SMP
even if you run single threaded apps.
> Can someone please explain how this works, and offer recommendations on
> motherboards and other configuration options that work?
There have been extensive discussion of SMP here in the last few weeks.
Search deja.com for linus smp and you'll get bunches of info.
I use Tyan pretty exclusively, because I've had very good luck with them
and they make a quality product. ASUS and others work well also.