I
NTEL
® X
EON
® P
ROCESSOR
7500 S
ERIES
U
NCORE
P
ROGRAMMING
G
UIDE
UNCORE PERFORMANCE MONITORING
2-128
Table 2-100. W_MSR_PMON_CTR_{3-0} Register – Field Definitions
Table 2-101. W_MSR_PMON_FIXED_CTR Register – Field Definitions
Note:
Due to an errata found within the Intel Xeon Processor 7500 Series, SW must consider
two special cases:
• If SW reads a counter whose value ends in 0x000000 or 0x000001, SW should subtract 0x1000000
to get the correct value.
• SW should not set up a sample interval whose value ends in either 0xfffffe or 0xffffff.
2.8.4
W-BOX Performance Monitoring Events
2.8.4.1
An Overview:
The W-Box’s primary offering to understanding the impact of the uncore on performance is the fixed
counter. This counter, which increments at the frequency of the uncore clock, can be used to add a time
element to numerous events across the uncore.
Beyond that, the W-Box provides a smattering of events that indicating when, and under what
circumstances, the W-Box throttled the chip due to power constraints.
2.8.5
W-Box Events Ordered By Code
summarizes the directly-measured W-Box events.
2.8.6
W-Box Performance Monitor Event List
This section enumerates Intel Xeon Processor 7500 Series uncore performance monitoring events for
the W-Box.
Field
Bits
HW
Reset
Val
Description
event_count
47:0
0 48-bit performance event counter
Field
Bits
HW
Reset
Val
Description
event_count
47:0
0 48-bit performance event counter
Table 2-102. Performance Monitor Events for W-Box Events
Symbol Name
Event
Code
Max
Inc/Cyc
Description
C_THROTTLE_TMP
0x00
1
Core Throttled due to Temp
C_C0_THROTTLE_DIE
0x01
1
Core Throttled in C0
PROCHOT
0x02
1
Prochot
C0_THROTTLE_PROCHOT
0x03
1
Core Throttled in C0 due to FORCEPR
C_CYCLES_TURBO
0x04
1
Core in C0 at Turbo
TM1_ON
0x07
1
TM1 Throttling On
RATIO_CHANGE_ABORT
0x08
1
Ratio Change Abort