BIOS boots AP cores in low-power mode

[rdos]

It seems like AP cores on my 6-core AMD machine must be booted into some kind of power-managed mode. The strange thing is that if I reboot from Windows XP into RDOS, it works just fine. The AP cores are running at full speed, and don't seem to stop as they hit hlt instructions. However, when the machine is cold-booted (or reseted with keyboard-port), it starts acting strange. There are no threads running, the keyboard ISRs work just fine, but the system is generally unresponsive. Sometimes it executes code, but mostly it appears hung.

Should it really by necessary to use ACPI to put AP cores into non-power managed modes at boot time? I can envision that it would be a good idea to shut-down cores when load is low, and restart them again as load increases, but why does BIOS put AP cores in low-power mode? Couldn't the AP cores execute some instruction to turn them off until they get the init message instead?

[Yashas]

Check your BIOS Settings for Default Options.And when you switch from xp it is perfect becaz XP Drivers will do it for you.It's better to make a ACPI becaz it will come in handy in future.Your system might be unresponsive because there might be some loop.I have experanice of the loops.
I hate those.