Intel i5-2520M FF8062700840017 User Manual

Datasheet

57

Based upon knowledge of the processor core and integrated graphics and memory 

controller thermal power, performance state, and temperature, power sharing control 

does the following:

• Utilizes processor core and internal graphics controller Intel Turbo Boost 

performance states to achieve their highest performance within the rated thermal 

power envelope. Intel Turbo Boost Technology enabled processors will offer a range 

of upside performance capability beyond their rated or guaranteed frequency.

• Controls the processor core and internal graphics controller Intel Turbo Boost 

performance states to ensure that overall MCP thermal power consumption does 

not exceed the specified MCP thermal power limit.

• Limits MCP component Intel Turbo Boost usage to ensure that each of the 

components' T

j,max

 value is not exceeded.

It is possible that the thermal influence between the MCP components could potentially 

cause a component to reach its T

j,max

, invoking undesirable component hardware auto-

throttling. It is expected that when running the TDP workload, power sharing control 

may limit the entire range of component Intel Turbo Boost capabilities (effectively, 

disabling them).

The principal component of the power sharing control architecture is the policy 

manager within the Intel Turbo Boost Technology driver which:

• Communicates with the graphics software driver to limit, or increase, internal 

graphics thermal power.

• Communicates with the processor core via the PCH to processor core PECI interface 

to limit, or increase, processor core thermal power.

The Intel Turbo Boost Technology policy manager will set a thermal power limit to 

which the graphics driver and processor core will adjust their Intel Turbo Boost 

Technology performance dynamically, to stay within the limit.

The processor PECI pin must be connected to the PCH PECI pin in order for Intel Turbo 

Boost Technology to properly function.

The processor input pin (ISENSE) informs the processor core of how much amperage 

the processor core is consuming. This information is provided by the processor core VR. 

The process will calculate its current power based upon the ISENSE input information 

and current voltage state. The internal graphics and memory controller power is 

estimated by the GFX driver using PMON.

Any error in power estimation or measurement may limit or completely eliminate the 

performance benefit of Intel Turbo Boost Technology. When a power limit is reached, 

Power sharing control will adaptively remove Intel Turbo Boost Technology states to 

remain with the MCP thermal power limit. Power sharing control assumes the power 

error is always accurate so if the ISENSE input reports power greater than the actual 

power, control mechanisms will lower performance before the actual TDP power limit is 

reached. Intelligent Power sharing will provide better overall Intel Turbo Boost 

Technology performance with increasing VR current sense accuracy. Designers and 

system manufacturers should study trade-offs on VR component accuracy 

characteristics, such as inductors, to find the best balance of cost vs. performance for 

their system price and performance targets.