White Paper on Turbo Boost Using Low Power Processor

Glossary Products Update for Turbo Boost with Low Power Processor
Glossary
Thermal Design Power (TDP): Thermal Design Power or Thermal Design Point designates
maximum amount of power a chip or a system is required to dissipate.
Load Current Monitor (IMON): An IMON is an analog output signal proportional to the VR’s
total output load current.
Advanced Configuration and Power Interface (ACPI): ACPI is an open-standard
specification for unified OS-centric device configuration and power management. It brings power
management into OS control, as opposed to BIOS central systems. ASL is the ACPI Source
Language used for specifying the desired device behavior.
C-state: The processor C-state is the processor’s capability to go into various low power idle
states (with varying wake-up latencies). Intel architecture-based processors have several C-
states representing parts that can be switched off to save power. C0 is the operational state,
meaning that the CPU is doing useful work. C1 is the first idle state: The clock running the
processor is gated; that is, the clock is prevented from reaching the core, effectively shutting it
down in an operational sense. C2 is the second idle state: The external I/O Controller Hub
blocks interrupts to the processor. And so on with C3, C4, and others.
P-states: The processor P-state is the capability of running the processor at different voltage
and/or frequency levels. Generally, P0 is the highest state resulting in maximum performance,
while P1, P2, and so on, will save power but at some penalty to CPU performance.
Intel
®
Turbo Boost Technology: Intel Turbo Boost Technology allows a processor’s cores to
run faster than the base operating frequency if the package is operating below its power, current,
and temperature specification limits. Intel Turbo Boost Technology is activated when the OS
requests the highest processor performance state (P0). Maximum frequency depends on the
number of active cores. The amount of time the processor spends in the Intel Turbo Boost
Technology state depends on the workload and operating environment, providing the extra
performance. Intel Turbo Boost Technology increases the performance of both
multi-threaded and single-threaded workloads.
4 Revision 1.0Enterprise Platforms and Services Division