32 Specification Update
HSD58. Performance Monitor Event DSB2MITE_SWITCHES.COUNT May Over
Count
Problem: The Performance Monitor Event DSB2MITE_SWITCHES.COUNT (Event ABH; Umask
01H) should count the number of DSB (Decode Stream Buffer) to MITE (Macro
Instruction Translation Engine) switches. Due to this erratum, the
DSB2MITE_SWITCHES.COUNT event will count speculative switches and cause the
count to be higher than expected.
Implication: The Performance Monitor Event DSB2MITE_SWITCHES.COUNT may report count higher
than expected.
Workaround: None identified.
Status: For the steppings affected, see the Summary Table of Changes.
HSD59. Performance Monitor Register UNC_PERF_GLOBAL_STATUS Not
Restored on Package C7 Exit
Problem: MSR_UNC_PERF_GLOBAL_STATUS (392H) is a global status register which indicates
the overflow of uncore performance monitor counters. The content of this register is
lost in package C7 state.
Implication: If any uncore performance monitor counter has overflowed before entering the
package C7 state, the MSR_UNC_PERF_GLOBAL_STATUS register will no longer reflect
the overflow after exiting C7 state.
Workaround: It is possible for the BIOS to contain a workaround for this erratum.
Status: For the steppings affected, see the Summary Table of Changes.
HSD60. Processor May Not Enter Package C6 or Deeper C-states When PCIe*
Links Are Disabled
Problem: If the PCIe links are disabled via Link Disable (Bus 0, Device 1, Functions [2:1], Offset
B0h, bit 4) and the PCIe controller is enabled (Bus 0, Device 0, Function 0, Offset 54h,
bits [2:1] = ’11), then the processor will be unable to enter Package C6 or deeper C-
states.
Implication: Due to this erratum, the process will not enter Package C6 or deeper C-states.
Workaround: It is possible for the BIOS to contain a workaround for this erratum.
Status: For the steppings affected, see the Summary Table of Changes.
HSD61. Performance Monitor Event For Outstanding Offcore Requests And
Snoop Requests May Over Count
Problem: The performance monitor event OFFCORE_REQUESTS_OUTSTANDING (Event 60H, any
Umask Value) should count the number of offcore outstanding transactions each cycle.
Due to this erratum, the counts may be higher than actual number of events.
Implication: The performance monitor events OFFCORE_REQUESTS_OUTSTANDING may reflect
counts higher than the actual number of events.
Workaround: None identified.
Status: For the steppings affected, see the Summary Table of Changes.