今天安装一台COMPAQ Proliant ML530服务器，Intel XEON 2.4 * 2 (HyperThreading)，操作系统用 FreeBSD 5.3，如果启用SMP和HT就应该是4CPU，结果安装上FreeBSD 5.3 Release后，发现没有找到SMP，找了N多原因，也将系统升级到 FreeBSD 5.3 Stable，结果SMP还是找不到（内核中已经加了options SMP），关了ACPI也不行，后来搜索了freebsd maillist，才找到答案：

进入 COMPAQ Proliant ML530 的 BIOS，我们选择的OS选项为Other，将其改成Win2000后就一切OK了，现在终于看到 4 cpu了。

%sysctl hw.ncpu
hw.ncpu: 4

但目前ACPI还是老是报错误：
代码:

ACPI APIC Table: <COMPAQ 00000083>
Timecounter "i8254" frequency 1193182 Hz quality 0
CPU: Intel(R) Xeon(TM) CPU 2.40GHz (2395.37-MHz 686-class CPU)
  Origin = "GenuineIntel"  Id = 0xf27  Stepping = 7
  Features=0xbfebfbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,C
byte 1415MOV,PAT,PSE36,CLFLUSH,DTS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,PBE>
  Hyperthreading: 2 logical CPUs
real memory  = 1073717248 (1023 MB)
avail memory = 1041162240 (992 MB)
FreeBSD/SMP: Multiprocessor System Detected: 4 CPUs
cpu0 (BSP): APIC ID:  0
cpu1 (AP): APIC ID:  1
cpu2 (AP): APIC ID:  6
cpu3 (AP): APIC ID:  7
MADT: Forcing active-low polarity and level trigger for SCI
ioapic0 <Version 1.1> irqs 0-15 on motherboard
ioapic1 <Version 1.1> irqs 16-31 on motherboard
ioapic2 <Version 1.1> irqs 32-47 on motherboard
ioapic3 <Version 1.1> irqs 48-63 on motherboard
npx0: [FAST]
npx0: <math processor> on motherboard
npx0: INT 16 interface
acpi0: <COMPAQ P22> on motherboard
acpi0: Power Button (fixed)
unknown: I/O range not supported
unknown: I/O range not supported
unknown: I/O range not supported
unknown: I/O range not supported
unknown: I/O range not supported
unknown: I/O range not supported
unknown: I/O range not supported
unknown: I/O range not supported
unknown: I/O range not supported
unknown: I/O range not supported
unknown: I/O range not supported
unknown: I/O range not supported
unknown: I/O range not supported
unknown: I/O range not supported
unknown: I/O range not supported
unknown: I/O range not supported