Intel Xeon E5-2600 Series Monitoring Manual page 68

• Definition: Counts the number of cycles when the iMC is in self-refresh and the iMC still has a
clock. This happens in some package C-states. For example, the PCU may ask the iMC to enter
self-refresh even though some of the cores are still processing. One use of this is for Monroe tech-
nology. Self-refresh is required during package C3 and C6, but there is no clock in the iMC at this
time, so it is not possible to count these cases.
POWER_THROTTLE_CYCLES
• Title: Throttle Cycles for Rank 0
• Category: POWER Events
• Event Code: 0x41
• Max. Inc/Cyc: 1, Register Restrictions: 0-3
• Definition: Counts the number of cycles while the iMC is being throttled by either thermal con-
straints or by the PCU throttling. It is not possible to distinguish between the two. This can be fil-
tered by rank. If multiple ranks are selected and are being throttled at the same time, the counter
will only increment by 1.
Table 2-70. Unit Masks for POWER_THROTTLE_CYCLES
Extension
RANK0
RANK1
RANK2
RANK3
RANK4
RANK5
RANK6
RANK7
PREEMPTION
• Title: Read Preemption Count
• Category: PREEMPTION Events
• Event Code: 0x08
• Max. Inc/Cyc: 1, Register Restrictions: 0-3
• Definition: Counts the number of times a read in the iMC preempts another read or write. Gener-
ally reads to an open page are issued ahead of requests to closed pages. This improves the page
hit rate of the system. However, high priority requests can cause pages of active requests to be
closed in order to get them out. This will reduce the latency of the high-priority request at the
expense of lower bandwidth and increased overall average latency.
Table 2-71. Unit Masks for PREEMPTION
Extension
RD_PREEMPT_RD
RD_PREEMPT_WR
68
Intel® Xeon® Processor E5-2600 Product Family Uncore Performance Monitoring
umask
[15:8]
bxxxxxxx1 DIMM ID:
Thermal throttling is performed per DIMM. We support 3 DIMMs per
channel. This ID allows us to filter by ID.
bxxxxxx1x DIMM ID
bxxxxx1xx DIMM ID
bxxxx1xxx DIMM ID
bxxx1xxxx DIMM ID
bxx1xxxxx DIMM ID
bx1xxxxxx DIMM ID
b1xxxxxxx DIMM ID
umask
[15:8]
bxxxxxxx1 Read over Read Preemption:
Filter for when a read preempts another read.
bxxxxxx1x Read over Write Preemption:
Filter for when a read preempts a write.
Description
Description
Reference Number: 327043-001