IBM Intel Xeon X7350 44E4243 Data Sheet

Product codes
44E4243
Page of 142
Features
116
Document Number: 318080-002
Enhanced Intel SpeedStep Technology creates processor performance states (P-states) 
or voltage/frequency operating points. P-states are lower power capability states within 
the Normal state as shown in 
. Enhanced Intel SpeedStep Technology 
enables real-time dynamic switching between frequency and voltage points. It alters 
the performance of the processor by changing the bus to core frequency ratio and 
voltage. This allows the processor to run at different core frequencies and voltages to 
best serve the performance and power requirements of the processor and system. The 
Intel
®
 Xeon
®
 Processor 7200 Series and 7300 Series have hardware logic that 
coordinates the requested voltage (VID) between the processor cores. The highest 
voltage requested from the four processor cores is selected for that processor package. 
Note that the front side bus is not altered; only the internal core frequency is changed. 
In order to run at reduced power consumption, the voltage is altered in step with the 
bus ratio.
The following are key features of Enhanced Intel SpeedStep Technology:
• Multiple voltage/frequency operating points provide optimal performance at 
reduced power consumption.
• Voltage/frequency selection is software controlled by writing to processor MSR’s 
(Model Specific Registers), thus eliminating chipset dependency.
— If the target frequency is higher than the current frequency, V
CC
 is incremented 
in steps (+12.5 mV) by placing a new value on the VID signals and the 
processor shifts to the new frequency. Note that the top frequency for the 
processor can not be exceeded.
— If the target frequency is lower than the current frequency, the processor shifts 
to the new frequency and V
CC
 is then decremented in steps (-12.5 mV) by 
changing the target VID through the VID signals.
7.4
System Management Bus (SMBus) Interface
The Intel
®
 Xeon
®
 Processor 7200 Series and 7300 Series package includes an SMBus 
interface which allows access to a memory component with two sections (referred to as 
the Processor Information ROM and the Scratch EEPROM). These devices and their 
features are described below.
Note:
The SMBus on-package thermal sensor has been removed and is no longer used. Refer 
 for details about the new digital thermometer and PECI interface.
The processor SMBus implementation uses the clock and data signals of the System 
Management Bus (SMBus) Specification
. It does not implement the SMBSUS# signal. 
For platforms which do not implement any of the SMBus features found on the 
processor, all of the SMBus connections, except SM_VCC, to the socket pins may be left 
unconnected (SM_CLK, SM_DAT, SM_EP_A[2:0], SM_WP).