Intel® Xeon® Processor E5-1600/E5-2600/E5-4600 Product Families 71
Datasheet Volume One
The client address may not be changed after PWRGOOD assertion, until the next power
cycle on the processor. Removal of a processor from its socket or tri-stating a processor
will have no impact to the remaining non-tri-stated PECI client addresses. Since each
socket in the system should have a unique PECI address, the SOCKET_ID strapping is
required to be unique for each socket.
2.5.3.4 C-states
The processor PECI client may be fully functional in most core and package C-states.
• The Ping(), GetDIB(), GetTemp(), RdPkgConfig() and WrPkgConfig() commands
have no measurable impact on CPU power in any of the core or package C-states.
• The RdIAMSR() command will complete normally unless the targeted core is in a C-
state that is C3 or deeper. The PECI client will respond with a completion code of
0x82 (see Tabl e 2-22 for definition) for RdIAMSR() accesses in core C-states that
are C3 or deeper.
• The RdPCIConfigLocal(), WrPCIConfigLocal(), and RdPCIConfig() commands will
not impact the core C-states but may have a measurable impact on the package C-
state. The PECI client will successfully return data without impacting package C-
state if the resources needed to service the command are not in a low power state.
— If the resources required to service the command are in a low power state, the
PECI client will respond with a completion code of 0x82 (see Tabl e 2-22 for
definition). If this is the case, setting the “Wake on PECI” mode bit as described
in Section 2.5.2.6 can cause a package ‘pop-up’ to the C2 state and enable
successful completion of the command. The exact power impact of a pop-up to
C2 will vary by product SKU, the C-state from which the pop-up is initiated and
the negotiated PECI bit rate.
Table 2-17. SOCKET ID Strapping
SOCKET_ID[1] Strap SOCKET_ID[0] Strap PECI Client Address
Ground Ground 0x30
Ground VTT 0x31
VTT Ground 0x32
VTT VTT 0x33
Table 2-18. Power Impact of PECI Commands vs. C-states
Command Power Impact
Ping() Not measurable
GetDIB() Not measurable
GetTemp() Not measurable
RdPkgConfig() Not measurable
WrPkgConfig() Not measurable
RdIAMSR() Not measurable. PECI client will not return valid data in core C-state that is C3 or deeper
RdPCIConfigLocal() May require package ‘pop-up’ to C2 state
WrPCIConfigLocal() May require package ‘pop-up’ to C2 state
RdPCIConfig() May require package ‘pop-up’ to C2 state