Intel BX80646I74770, CM8064601466200 Fan Speed Control Scheme with Digital Thermal Sensor DTS

Thermal Management—Processor

Table 26. Digital Thermal Sensor (DTS) 1.1 Thermal Solution Performance Above

TCONTROL

Processor		ΨCA at DTS =	ΨCA at DTS = -1	ΨCA at DTS = -1	ΨCA at DTS = -1
TDP		TCONTROL1, 2	At System	At System	At System TAMBIENT-
		At System TAMBIENT-	TAMBIENT-MAX	TAMBIENT-MAX	MAX = 50 °C
		MAX = 30 °C	= 40 °C	= 45 °C
84 W		0.627	0.390	0.330	0.270
65 W		0.793	0.482	0.405	0.328
45 W		1.207	0.699	0.588	0.477
35 W		1.406	0.753	0.610	0.467
Notes: 1.	ΨCA at "DTS = TCONTROL" is applicable to systems that have an internal TRISE (TROOM temperature
	to Processor cooling fan inlet) of less than 10 °C. In case the expected TRISE is greater than 10
	°C, a correction factor should be used as explained below. For each 1 °C TRISE above 10 °C, the
	correction factor (CF) is defined as CF = 1.7 / (processor TDP)
2.	Example: A chassis TRISE assumption is 12 °C for a 95 W TDP processor:
	CF = 1.7 / 95 W = 0.018 /W

For TRISE > 10 °C

ΨCA at TCONTROL = (Value provide in Column 2) – (TRISE – 10) * CF ΨCA = 0.627 – (12 – 10) * 0.018 = 0.591 °C/W

In this case, the fan speed should be set slightly higher, equivalent to ΨCA = 0.591 °C/W

5.4Fan Speed Control Scheme with Digital Thermal Sensor (DTS) 2.0

To simplify processor thermal specification compliance, the processor calculates the DTS Thermal Profile from TCONTROL Offset, TCC Activation Temperature, TDP, and the Thermal Margin Slope provided in the following table.

Note: TCC Activation Offset is 0 for the processors.

Using the DTS Thermal Profile, the processor can calculate and report the Thermal Margin, where a value less than 0 indicates that the processor needs additional cooling, and a value greater than 0 indicates that the processor is sufficiently cooled. Refer to the processor Thermal Mechanical Design Guidelines (TMDG) for additional information (see Related Documents).

Desktop 4th Generation Intel® Core™ Processor Family, Desktop Intel® Pentium® Processor Family, and Desktop Intel® Celeron® Processor Family

December 2013	Datasheet – Volume 1 of 2
Order No.: 328897-004	73