Vol. 3C 35-173

MODEL-SPECIFIC REGISTERS (MSRS)

27:16

Reserved.

28

Package

Programmable Ratio Limit for Turbo Mode (R/O) 
When set to 1, indicates that Programmable Ratio Limits for Turbo 

mode is enabled, and when set to 0, indicates Programmable Ratio 

Limits for Turbo mode is disabled.

29

Package

Programmable TDP Limit for Turbo Mode (R/O) 
When set to 1, indicates that TDP Limits for Turbo mode are 

programmable, and when set to 0, indicates TDP Limit for Turbo 

mode is not programmable.

31:30

Reserved.

32

Package

Low Power Mode Support (LPM) (R/O) 
When set to 1, indicates that LPM is supported, and when set to 0, 

indicates LPM is not supported.

34:33

Package

Number of ConfigTDP Levels (R/O) 
00: Only Base TDP level available.
01: One additional TDP level available.
02: Two additional TDP level available.
11: Reserved

39:35

Reserved.

47:40

Package

Maximum Efficiency Ratio (R/O) 
The is the minimum ratio (maximum efficiency) that the processor 

can operates, in units of 100MHz.

55:48

Package

Minimum Operating Ratio (R/O) 
Contains the minimum supported
operating ratio in units of 100 MHz.

63:56

Reserved.

E2H

226

MSR_PKG_CST_CONFIG_

CONTROL

Core

C-State Configuration Control (R/W) 
Note: C-state values are processor specific C-state code names, 

unrelated to MWAIT extension C-state parameters or ACPI C-States.
See http://biosbits.org.

Table 35-23.  Additional MSRs Supported by 3rd Generation Intel® Core™ Processors (based on Intel® 

microarchitecture code name Ivy Bridge) (Contd.)

Register 

Address

Register Name

Scope

Bit Description

 Hex

Dec