Table 14. Digital Multimeter; Table 15. Power Measurement Resistor For Power Rails - Intel ® Core i7 User Manual

power measurement resistors are 2mOhm by default. Power on a particular subsystem is
calculated using the following formula:
It is recommended that the user use a high precision digital multimeter tool such as the
Agilent* 34401A digital multi-meter. Refer to
digital multi-meter (Agilent 34401A) versus a standard precision digital multimeter (Fluke*
79).

Table 14. Digital Multimeter

Agilent 34401A (6 ½ digit display)
Specification:
Min Voltage Displayed:
Calculated Power:
Max Voltage Displayed:
Calculated Power:
Error in Power:
As Table 14
standard digital multimeter is ~33 times more accurate.
The Power Measurement resistors provided for the various rails are listed in

Table 15. Power Measurement Resistor for Power Rails

Dev Kit Manual
R = value of the sense resistor (typically 0.002Ω)
V = the voltage difference measured across the sense resistor.
Sense Resistor Value:
Voltage Difference Across Resistor:
Calculated Power:
(±0.0030% of
reading)
+ (±0.0030% of
range)
1.49193mV
1.1129mW
1.49206mV
1.1131mW
±0.009%
shows the precision achieved by using a high precision digital multimeter versus a
Voltage Rail Name
GVR_VBAT
+VGFX_CORE
2
V

P
R
Table 14 for a comparison of a high precision
EXAMPLE SYSTEM
0.002Ω
1.492mV (746mA)
1.113mW
Fluke 79 (3 digit display)
Specification:
Min Voltage Displayed:
Calculated Power:
Max Voltage Displayed:
Calculated Power:
Error in Power:
REFDES of the
Power Measurement Resistor
R1E2
R2D11
±0.09% ±2 digits
1.47mV
1.08mW
1.51mV
1.14mW
±0.3%
Table 15:
39 323094