[Wylug-discuss] Linux on Intel 64-Bit Xeon

[Dave Fisher]

In one of their regular sales, Dell are currently offering UK businesses
what look like very attractive prices on some of their rack-mounted dual
64-Bit Xeon servers.

I need a cheap but pretty fast web/mail/database/application server. The
Dell Poweredge 1850 looks superficially like it will do the trick.

   http://www1.euro.dell.com/content/products/productdetails.aspx/pedge_1850?c=uk&cs=ukbsdt1&l=en&s=bsd

My problem is that I've completely lost track of the ever-more-varied
CPU families available ... my excuse is that we are now long past the
days when consumers had to worry about having enough cycles for
run-of-the-mill applications ... and there are so many variations to
consider.

So my questions are:

   1. Which Intel 64-bit architecture is a 'Dual 64-Bit Xeon'?  
   
   As I understand it, Intel has two 64-bit architectures (one that is
   and one that isn't 32-bit compatible).  Am I right about this?

   2. Does the label '64-Bit Xeon' apply to both, and if so, how do you
   tell the difference?

   3. What is the state of kernel and distro support for either
   architecture?

   4. Assuming that there is fairly good distro support for the kit on
   offer (Dell suggest RH/SuSE), is the CPU performance reasonable for
   the price? 
   
   Pre-built dual Opterons look out of my price range and I really don't
   have time for self builds these days (it's not the building per se
   that's the problem, it's the research time required to ensure
   efficient component compatibility).

I am sorry to be slightly off-topic, but I am having trouble filtering
the noise from google results, and these are _ultimately_ Linux
compatibility questions.

Dave