This Notes are supplied by
Ali Faiez Taha

1- At first you need to upgrade the Motherboard's BIOS. Uprade it to
version 1.23, or 1.25.
Get the upgrade file from Intel site:
http://support.intel.com/support/motherboards/server/se7500cw2/

See the session :

Software & Drivers
  Promise* Fastcheck Utility
  Crisis Files for BIOS 1.23
  Latest BIOS - BIOS 1.25
  Hotswap Controller Backplane Driver for Microsoft Windows* 2000

2- Then disable the BIOS item Hyperthreading

3- Apply the patch for apic.h will fix the problem in any case with an
SE7500CW2 motherboard.

* Michael Richards wrote:
Please try revision 1.19 of sys/i386/include/apic.h on current, or
you can backport just that change to the same file on -stable.
I just tried this out on the machine I was trying to get working
and I can confirm that it does indeed work. Attached is a patch for
the version 1.14.2.1 of apic.h that comes with 4.7.
Just sticking the file in does not work because of some other defines.
What will it take to get this patch into 4.7/5.0?

-Michael

 *** apic.h      Mon Mar 17 16:26:45 2003
 --- apic.h.old  Mon Mar 17 16:27:35 2003

 ***************
 *** 310,316 ****

   /* fields in ICR_HIGH */
 ! #define APIC_ID_MASK          0xff000000

   /* fields in LVT1/2 */
 --- 310,316 ----

   /* fields in ICR_HIGH */
 ! #define APIC_ID_MASK          0x0f000000

   /* fields in LVT1/2 */

4- Compile your Kernel with :
options         SMP             # Symmetric MultiProcessor Kernel
options         APIC_IO         # Symmetric (APIC) I/O
options         CPU_ENABLE_SSE  #Enables SSE/MMX2 instructions support

The SMP FreeBSD mail list may help more.

If possible subscribe to freebsd-smp@FreeBSD.ORG

I'm working with FreeBSD 4.8RC2 and the SMP are running very well.