Dual Xeons on Iwill DP533 motherboard

Mike O'Brien mikeobrien at spamcop.net
Thu Jan 22 21:24:58 PST 2004

	I run -STABLE (4.9) on an Iwill DP533 motherboard with dual
2.4GHz Xeon processors.  I enable hyperthreading, and till now, I've
had to put an ugly little hack into the mp_machdep.c file because the
Iwill BIOS reported funny APIC ID numbers for the processors.

	This note, which is more or less for the archives, is to say
that I just upgraded the BIOS on this motherboard to the latest release
on the Iwill web site (http://www.iwillusa.com).  I had not previously
done this because no sane person upgrades the BIOS if it's not giving
them any problems.

	To my shock, it turns out I _was_ having BIOS problems.  There
have been occasional odd hangs of this machine under XP (it's a dual-boot)
though FreeBSD has been solid as a rock.  The clincher came when the
client for Second Life started hanging the machine every five minutes.
In desperation I upgraded the BIOS to the June, 2003 (latest as of
this message) release, and the problem went away completely.  Apparently
interrupts were being misvectored or something.

	That isn't all.  FreeBSD would no longer boot until I disabled
hyperthreading in the BIOS setup.  On a hunch, I backed out my hack,
reenabled hyperthreading, and FreeBSD-STABLE now correctly finds the four
virtual processor cores without it.  Apparently this update fixes the
funny APIC numbering.

	Anyone running an Iwill DP533 motherboard should install this
BIOS upgrade, it seems.

Mike O'Brien

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