All, I booted with 2.6.18 kernel with only "noapic acpi=off" I removed the apci=off and the kernel still dumps with a bunch of messages about acpi. I have installed 2.6.34 kernel on the box. I can boot without the acpi=off and I get all 4 cores on this box. if I put in the acpi=off it only reports one core in /proc/cpuinfo Jerry