Re: [rhn-users] Intel or AMD

[Eric Eisenhart <eric eisenhart sonoma edu>]

Dominique Demore wrote:
> We are currently in the process of selecting 2 new servers to run new Student Information System. Both systems will be
> running version 3 (AS). One server will be the Oracle 9i database and the other the Oracle Application Server.
> My questions is: Since I have the chance of selecting either an Intel Xeon processor or AMD Optron, which should I
> select. What about the Itaniums?
>
> Beside the 64 bit processing of the Optron, are there any other advantages? Any disadvantages?
>
> Any thoughts or comments?

Single CPU?  Dual CPU?  Quad CPU?

Opteron's use a Non-Uniform Memory Architecture (NUMA).  Specifically, 
each CPU has its own connection to its own bank of RAM.  Memory is 
accessed via a different path than I/O.  Then there's connections 
between the CPUs in case one CPU needs to access RAM or I/O hooked up to 
the other processor.  Xeons and Itaniums have a Front Side Bus that all 
access to all I/O and memory goes through, leaving you with a single 
bottleneck.

So, it depends on the exact Opteron motherboard design that you're 
talking about, but with a dual or quad CPU system, an Opteron will make 
a much better database server than a Xeon or an Itanium (assuming the 
motherboard is designed right.)  I've looked at the design specs for 
Sun's Opteron servers and HP's Opteron servers, and both are solid 
designs that put RAM in the right places.  In both cases, on the 
dual-opteron design all I/O is off of one CPU (with ram on both) and on 
the system that can handle more than 2 CPUs, I/O is spread between 2 of 
the CPUs.  (and a bank of RAM on every CPU, of course)  I haven't 
checked if they've updated, but about a year ago IBM's Opteron systems 
looked kind of sub-par (no on-board RAID); designed for compute clusters 
not database servers.  I have no idea about other vendors; quality can 
vary widely.  There are definitely some Opteron boards out there that 
put all the RAM and I/O on one CPU, which makes the system about as slow 
 as if it had a front-side bus.

Check for support from Oracle.  An Opteron can still make a very speedy 
server for running 32-bit applications, but you're best off if the 
specific things you're running actually support the "x86_64/AMD64/ia32e" 
64-bit instructions.

Also, go read this article, and make sure to look at the diagrams:
http://www.samag.com/documents/s=9408/sam0411b/0411b.htm
--
Eric Eisenhart <eric eisenhart sonoma edu>
Linux/Unix Systems Administrator
Office: Schulz 1050A, (707) 664-3099
AIM: ericeisenhart, ICQ: 156218985
Sonoma State University, IT