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Vol. 3C 35-231

MODEL-SPECIFIC REGISTERS (MSRS)

23:16

Package

Maximum Ratio Limit for 11C

31:24

Package

Maximum Ratio Limit for 12C

39:32

Package

Maximum Ratio Limit for 13C

47:40

Package

Maximum Ratio Limit for 14C

55:48

Package

Maximum Ratio Limit for 15C

63:56

Package

Maximum Ratio Limit for 16C

606H

1542

MSR_RAPL_POWER_UNIT

Package

Unit Multipliers used in RAPL Interfaces (R/O) 

3:0

Package

Power Units
See Section 14.9.1, “RAPL Interfaces.”

7:4

Package

Reserved

12:8

Package

Energy Status Units
Energy related information (in Joules) is based on the multiplier, 

1/2^ESU; where ESU is an unsigned integer represented by bits 

12:8. Default value is 0EH (or 61 micro-joules)

15:13

Package

Reserved

19:16

Package

Time Units
See Section 14.9.1, “RAPL Interfaces.”

63:20

Reserved

618H

1560

MSR_DRAM_POWER_LIMIT

Package

DRAM RAPL Power Limit Control (R/W) 
See Section 14.9.5, “DRAM RAPL Domain.”

619H

1561

MSR_DRAM_ENERGY_

STATUS

Package

DRAM Energy Status (R/O) 
Energy consumed by DRAM devices

31:0

Energy in 15.3 micro-joules. Requires BIOS configuration to enable 

DRAM RAPL mode 0 (Direct VR).

63:32

Reserved

61BH

1563

MSR_DRAM_PERF_STATUS

Package

DRAM Performance Throttling Status (R/O) See Section 14.9.5, 

“DRAM RAPL Domain.”

61CH

1564

MSR_DRAM_POWER_INFO

Package

DRAM RAPL Parameters (R/W) 
See Section 14.9.5, “DRAM RAPL Domain.”

639H

1593

MSR_PP0_ENERGY_STATUS Package

Reserved (R/O) 
Reads return 0

690H

1680

MSR_CORE_PERF_LIMIT_RE

ASONS

Package

Indicator of Frequency Clipping in Processor Cores (R/W)
(frequency refers to processor core frequency)

0

PROCHOT Status (R0)
When set, processor core frequency is reduced below the operating 

system request due to assertion of external PROCHOT.

1

Thermal Status (R0)
When set, frequency is reduced below the operating system 

request due to a thermal event.

Table 35-34.  Additional MSRs Common to Intel® Xeon® Processor D and Intel Xeon Processors E5 v4 Family Based 

on the Broadwell Microarchitecture

Register 

Address

Register Name

Scope

Bit Description

 Hex

Dec