Kontron COMe-bCD2 - Manual (Page 42)

8 Important Technology Information
Kontron User's Guide ETXexpress® CD 42
Automatic mode does not require any additional hardware, software drivers, or interrupt handling
routines.
Note: With a properly designed thermal solution, the TCC is only active for very short periods, hence processor
performance impact is expected to be so minor that it would not be detectable.
The Intel® processor supports the THERMTRIP# signal for catastrophic thermal protection.
In the event of a catastrophic cooling failure, the processor will automatically shut down when the
silicon has reached a temperature of approximately 125°C. At this point the system BUS signal
THERMTRIP# will go active.
THERMTRIP# activation is independent of processor activity and does not generate any bus cycles.
8.2.1 Summary
Thermal Control Circuit reduces performance when the processor reaches its max. operating temperature
(100°C). THERMTRIP# shuts down the system in case of catastrophic cooling failure.
8.3 Processor Performance Control
The Intel® processor can run in different performance states (multiple frequency/voltage operating
points). The CPU performance can be altered while the computer is functioning. This allows the
processor to run at different core frequencies and voltages depending on CPU thermal state and OS
policy.
Windows XP includes built-in processor performance control to operate the processor more efficiently
when it is not fully utilized. Win2k, WinME and Win9x do not support processor performance control.
Special software is required for OSes not capable of processor performance control.
In Windows, the processor performance control policy is linked to the Power Scheme setting in the
control panel power option applet.
Note: Windows always runs at the highest performance state when the “Home/Office” or “Always On” power
scheme is selected.
For a more detailed information about processor performance control, see:
Chapter 8 of the ACPI Specification Revision 2.0c available at www.acpi.info Windows platform design note
at: http://www.microsoft.com/whdc/hwdev/tech/onnow/procperfctrl.mspx