Soldato
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I thought this information would be useful to people over clocking regarding thermal relationships so that C2Q and C2D temperatures can be uniformly tested, accurately calibrated, and properly monitored. Basically a guide for all.
This Guide requires basic familiarity with computer terminology and BIOS menus, but does not require knowledge of unnecessarily diverse or complex technical details. Certain strict definitions have therefore been relaxed to simplify concepts and enhance comprehension.
Intel provides separate thermal specifications for 2 different sensor types; a single Case Thermal Diode located within the CPU die between the Cores, and Digital Thermal Sensors located within each Core. The Case Thermal Diode measures Tcase (Temperature Case), which is commonly known as CPU temp, and the Digital Thermal Sensors measure Tjunction (Temperature Junction), which is commonly known as Core temp. Since these sensors measure 2 distinct thermal levels, there is a constant temperature difference between them, which is referred to as Tcase to Junction Delta. C2Q`s have 1 Tcase and 4 Junction sensors, while C2D`s have 1 Tcase and 2 Junction sensors.
Intel does not provide information which correlates Tcase and Junction specifications to normal temperatures and Deltas. Consequently, there is much confusion among users regarding temperature monitoring, software utilities, test methods, Calibrations and Offsets, so Results can be difficult to decipher and compare. When listing Idle & Load test Results, it's also necessary to list the Variables as shown below:
Results
Tcase = Idle & Load
Tjunction = Idle & Load, hottest Core
Variables
Ambient = Room Temp
Chipset = Model
C2Q / C2D = Model
CPU Cooler = Model
Frequency = CPU Clock
Load = Test Program
Motherboard = Model
Stepping = Revision
Vcore = CPU Voltage
Section 2: Specifications
CPU`s can be identified by the product code on the retail box, the integrated heat spreader on the CPU, and by CPU-Z. Use CPU-Z (see Section 8) to read the Revision field below the Stepping field, then record the characters. Use the following link to reference the CPU with Intel's Spec# for Maximum Case Temperature, Stepping (which determines Maximum Junction Temperature), Thermal Design Power and Vcore:
http://processorfinder.intel.com/Default.aspx
Intel`s Thermal Specifications:
The thermal specification shown is the maximum case temperature at the maximum Thermal Design Power (TDP) value for that processor. It is measured at the geometric center on the topside of the processor integrated heat spreader.
For processors without integrated heat spreaders such as mobile processors, the thermal specification is referred to as the junction temperature (Tj). The maximum junction temperature is defined by an activation of the processor Intel® Thermal Monitor. The Intel Thermal Monitor's automatic mode is used to indicate that the maximum TJ has been reached.
Section 3: Interpretation
The first part of the spec refers to a single measuring point on the Integrated Heat Spreader (IHS). Since a thermocouple is embedded in the IHS for lab tests only, IHS temperature is replicated using a CPU Case Thermal Diode integrated between the Cores. Maximum Case Temperature is determined by Spec#. The CPU Case Thermal Diode is how Tcase is measured, and is the CPU temperature displayed in BIOS and in the software utility SpeedFan.
The second part of the spec refers to mobile processors without Integrated Heat Spreaders (IHS). Although desktop CPU`s have an IHS, both variants measure the hot spots within each Core using Digital Thermal Sensors (DTS). Maximum Junction Temperatures are determined by Stepping. The Digital Thermal Sensors are how Tjunction is measured, and are the Core temperatures displayed in the software utilities Core Temp and SpeedFan.
Section 4: Thermal Flow
Heat originates within the Cores, where Tjunction sensors are located within the hot spots of each Core. From the bottom of the Cores, heat dissipates throughout the CPU Case, which creates a thermal gradient toward the center of the Die, where the Tcase sensor is located. Heat then dissipates through the socket and motherboard to air inside the computer case. From the top of the Cores, heat dissipates through the Integrated Heat Spreader and CPU cooler to air inside the computer case. Safe and sustainable temperatures are determined by CPU cooling efficiency, computer case cooling efficiency, Ambient temperature, Vcore, clock speed, Stepping and Load. Tjunction is always higher than Tcase, and Tcase is always higher than Ambient.
Section 5: Findings
(A) Depending upon Stepping, the Delta between Tcase and Tjunction is 10c +/- 3 (or) 15c +/- 3.
(B) Tcase is acquired on the CPU Die from the CPU Case Thermal Diode as an analog level, which is converted to a digital value by the super I/O chip on the motherboard. The digital value is Calibrated in BIOS and displayed by temperature software.
(C) Tjunction is acquired within the Cores from Thermal Diodes as analog levels which are converted to digital values by the Digital Thermal Sensors (DTS) within each Core. The digital values are factory Calibrated and displayed by temperature software.
(D) Tcase and Tjunction are both acquired from Thermal Diodes, however, analog to digital (A to D) conversions are executed by different devices in separate locations. BIOS Calibrations, factory DTS Calibrations and temperature software can all be erroneous.
(E) Core Temp, CPU-Z, Crystal CPUID and SpeedFan will be used for Calibrating Tcase and Tjunction at Idle. Prime95 will then be used for Load testing and SpeedFan will be used for temperature monitoring.
Additional Specifications
Ambient Temperature = 22c
Idle to Load Delta Max = 25c
Thermal Diode Accuracy = +/-1c
Tjunction Max = 100c (B3, G0, L2, M0 Stepping)
Tjunction Max = 85c (B2 Stepping)
Section 6: Scale
Safe and sustainable temperatures vary according to Spec# and Stepping. The temperature Scales shown below illustrate the maximum 25c Delta between Idle and Load, and the typical 10c +/- 3 (or) 15c +/- 3 Delta between Tcase and Tjunction among C2Q / C2D variants. Although the Delta between Tcase and Tjunction is constant, these temperatures do not always scale in a precisely linear manner with respect to one another, due to Variables such as Vcore, clock speed, Stepping and Load. Idle at very low Vcore and clock on G0 Stepping may cause Tcase to Tjunction Delta hottest Core to indicate less than 7c, while 100% Workload at very high Vcore and overclock on B2 Stepping at may cause Tcase to Tjunction Delta hottest Core to exceed 18c.
If temperatures increase beyond Hot Scale, then ~ 5c below Tjunction Max, Throttling is activated. The Digital Thermal Sensors (DTS) are used to trigger Intel`s TM1 and TM2 technologies for frequency, multiplier and Vcore Throttling within individual Cores. If Core temperatures increase further to Tjunction Max, then Shutdown occurs. Since Tcase indicates CPU Die temperature only, it is not used for Throttle or Shutdown activation, however, referring to the CPU`s shown below under Scale 1 as examples, Tjunction Throttle temperature is ~ 95c, so Tcase would be ~ 85c, which would far exceed Tcase Max. As Tcase to Tjunction Deltas are constant, Tcase Max is always the limiting specification for temperatures.
Since Intel does not correlate information concerning Tcase and Tjunction into a convenient format, use CPU-Z (see Section 8) to read processor information including the Revision field below the Stepping field, then choose a Scale below which applies to the CPU being tested. Scales are ordered from highest to lowest Tcase Max.
Scale 1: Duo
E4x00: Tcase Max 73c, M0 Stepping, Tjunction Max 100c, Vcore Max 1.325, TDP 65w, Delta 10c
E21x0: Tcase Max 73c, M0 Stepping, Tjunction Max 100c, Vcore Max 1.312, TDP 65w, Delta 10c
E6x50: Tcase Max 72c, G0 Stepping, Tjunction Max 100c, Vcore Max 1.350, TDP 65w, Delta 10c
E6540: Tcase Max 72c, G0 Stepping, Tjunction Max 100c, Vcore Max 1.350, TDP 65w, Delta 10c
-Tcase/Tjunction-
--70--/--80--80-- Hot
--65--/--75--75-- Warm
--60--/--70--70-- Safe
--25--/--35--35-- Cool
Scale 2: Quad
Q6x00: Tcase Max 71c, G0 Stepping, Tjunction Max 100c, Vcore Max 1.372, TDP 95w, Delta 10c
-Tcase/Tjunction-
--70--/--80--80--80--80-- Hot
--65--/--75--75--75--75-- Warm
--60--/--70--70--70--70-- Safe
--25--/--35--35--35--35-- Cool
Scale 3: Quad
QX6x50: Tcase Max 65c, G0 Stepping, Tjunction Max 100c, Vcore Max 1.372, TDP 130w, Delta 10c
QX6700: Tcase Max 65c, B3 Stepping, Tjunction Max 100c, Vcore Max 1.372, TDP 130w, Delta 10c
-Tcase/Tjunction-
--65--/--75--75--75--75-- Hot
--60--/--70--70--70--70-- Warm
--55--/--65--65--65--65-- Safe
--25--/--35--35--35--35-- Cool
Scale 4: Quad
Q6600: Tcase Max 62c, B3 Stepping, Tjunction Max 100c, Vcore Max 1.372, TDP 105w, Delta 10c
-Tcase/Tjunction-
--60--/--70--70--70--70-- Hot
--55--/--65--65--65--65-- Warm
--50--/--60--60--60--60-- Safe
--25--/--35--35--35--35-- Cool
Scale 5: Duo
E6x00: Tcase Max 61c, L2 Stepping, Tjunction Max 100c, Vcore Max 1.325, TDP 65w, Delta 15c
E4x00: Tcase Max 61c, L2 Stepping, Tjunction Max 100c, Vcore Max 1.325, TDP 65w, Delta 15c
E21x0: Tcase Max 61c, L2 Stepping, Tjunction Max 100c, Vcore Max 1.312, TDP 65w, Delta 15c
X6800: Tcase Max 60c, B2 Stepping, Tjunction Max 85c, Vcore Max 1.3525, TDP 75w, Delta 15c
E6x00: Tcase Max 60c, B2 Stepping, Tjunction Max 85c, Vcore Max 1.3525, TDP 65w, Delta 15c
E6x20: Tcase Max 60c, B2 Stepping, Tjunction Max 85c, Vcore Max 1.3525, TDP 65w, Delta 15c
-Tcase/Tjunction-
--60--/--75--75-- Hot
--55--/--70--70-- Warm
--50--/--65--65-- Safe
--25--/--40--40-- Cool
Scale 6: Quad
QX6800: Tcase Max 55c, B3 Stepping, Tjunction Max 100c, Vcore Max 1.372, TDP 130w, Delta 10c
-Tcase/Tjunction-
--55--/--65--65--65--65-- Hot
--50--/--60--60--60--60-- Warm
--45--/--55--55--55--55-- Safe
--25--/--35--35--35--35-- Cool
7: Parameters
(A) Vcore should not exceed 1.5 volts.
(B) NO temperatures can be less than Ambient.
(C) Normal Ambient temperature is specified at 22c.
(D) All temperatures increase as Ambient, clock and Vcore increase.
(E) Tcase Idle is always higher than Ambient, even if less than 0.5c.
(F) Tjunction Idle hottest Core is typically no less than 10c +/- 3 higher than Ambient.
(G) Tcase to Tjunction Delta is ~ 10c on B3 / G0 / M0 Stepping and ~ 15c on B2 / L2 Stepping.
(H) Tjunction Load should not exceed Hot Scale for the CPU being tested.
(I) Tcase Load should not exceed Hot Scale for the CPU being tested.
(J) Tjunction Idle and Load Results are always hottest Core.
(K) Idle to Load Delta should not exceed 25c.
Section 8: Tools
Core Temp, CPU-Z, Crystal CPUID and SpeedFan will be used for Calibrating Tcase and Tjunction at Idle. Prime95 will then be used for Load testing and SpeedFan will provide temperature monitoring. Use the following links to download and install these utilities:
Core Temp 0.95.4 (Beta): http://www.thecoolest.zerobrains.com/CoreTemp
CPU-Z 1.41: http://www.cpuid.com/cpuz.php
Crystal CPUID 4.13.1.340: http://crystalmark.info/download/i [...] ystalCPUID
Prime95 25.4: http://www.mersenneforum.org/showthread.php?t=8981
SpeedFan 4.33 displays Tcase and Tjunction sensors: http://www.almico.com/speedfan.php
Note 1: Core Temp is an excellent utility, however, it has a fundamental flaw in terminology, which creates confusion in the CPU temperature community, by obscuring the distinction between temperature and specification. Core Temp shows Tjunction 85c (or 100c), which is an incorrect term. The proper expression is Tjunction Max 85c (or 100c), which is the term defined by Intel as shown above in the Specifications section, and as represented below:
Tjunction = Core temperature
Tjunction Max = Shutdown
(A) Junction Temperature is a thermal measurement because it scales, thus the term TJ, or Tjunction, which is synonymous with Core temperature.
(B) Maximum Junction Temperature is a specification because it does not scale, thus the term TJ Max, or Tjunction Max, which is synonymous with Shutdown.
(C) ~ 5c below Tjunction Max Throttling is activated. If Tjunction Max is reached, Shutdown occurs, which is either 85c or 100c, and is determined by Stepping.
With this information in mind, it is recommended that Core Temp be used during Calibrations to cross-reference CPU-Z Stepping Revision and SpeedFan Core temperatures.
Note 2: When using Prime95 for the first time, it is necessary to click on Advanced, then click on Round off checking so that errors caused by instabilities will be flagged as they occur. Prime95 will expose insufficient CPU cooling and computer case cooling, or excessive Vcore and overclock. At no other time will a CPU be as heavily loaded, or display higher temperatures, even when OC'd during worst-case loads such as gaming or video editing. Prime95 can be used with SpeedFan to observe CPU temps, while stress testing for system stability. During single threaded gaming and applications, Core 0 typically carries heavier loads and higher temps than other Cores.
Note 3: SpeedFan is very flexible and is the temperature monitoring utility of choice. SpeedFan detects and labels thermal sensors according to various motherboard, chipset and super I/O chip configurations, so the Tcase label can be CPU, Temp 1, Temp 2, or Temp 3. Even if Tcase is labeled as CPU, it is still necessary to confirm the identity of Tcase prior to conducting Calibrations. Run Prime95 and note which SpeedFan temperature scales with an Idle to Load Delta similar to the Cores. This will identify the label corresponding to Tcase. Labels can later be renamed using the Configure button, (see Section 11). If a temperature shows a flame icon, this indicates alarm limits which require adjustment. Use the Configure button to set CPU and Core temp alarms to Safe Scale. If a temperature shows Aux 127, this is simply an unassigned input which can be disabled using the Configure button. CPU`s with Steppings which are Tjunction Max 100c typically require +15c Core Offsets. See Section 11.
Note 4: The software utility (TAT) Thermal Analysis Tool at maximum settings will simulate 100% Thermal Load, which would equate to Prime95 at 114% Workload. This provides the most extreme testing available for CPU and system cooling efficiency. Since TAT is coded to measure Notebook temps, it identifies a C2D as Pentium M. As Notebooks have no Integrated Heat Spreader, thermal scaling differs from desktops CPU`s, so TAT indicates ~ 2c lower, and depending on Variables, temps may be Offset by more than 15c. It is therefore recommended that TAT be used for extreme thermal testing only, and temps regarded as unreliable.
continued below
This Guide requires basic familiarity with computer terminology and BIOS menus, but does not require knowledge of unnecessarily diverse or complex technical details. Certain strict definitions have therefore been relaxed to simplify concepts and enhance comprehension.
Intel provides separate thermal specifications for 2 different sensor types; a single Case Thermal Diode located within the CPU die between the Cores, and Digital Thermal Sensors located within each Core. The Case Thermal Diode measures Tcase (Temperature Case), which is commonly known as CPU temp, and the Digital Thermal Sensors measure Tjunction (Temperature Junction), which is commonly known as Core temp. Since these sensors measure 2 distinct thermal levels, there is a constant temperature difference between them, which is referred to as Tcase to Junction Delta. C2Q`s have 1 Tcase and 4 Junction sensors, while C2D`s have 1 Tcase and 2 Junction sensors.
Intel does not provide information which correlates Tcase and Junction specifications to normal temperatures and Deltas. Consequently, there is much confusion among users regarding temperature monitoring, software utilities, test methods, Calibrations and Offsets, so Results can be difficult to decipher and compare. When listing Idle & Load test Results, it's also necessary to list the Variables as shown below:
Results
Tcase = Idle & Load
Tjunction = Idle & Load, hottest Core
Variables
Ambient = Room Temp
Chipset = Model
C2Q / C2D = Model
CPU Cooler = Model
Frequency = CPU Clock
Load = Test Program
Motherboard = Model
Stepping = Revision
Vcore = CPU Voltage
Section 2: Specifications
CPU`s can be identified by the product code on the retail box, the integrated heat spreader on the CPU, and by CPU-Z. Use CPU-Z (see Section 8) to read the Revision field below the Stepping field, then record the characters. Use the following link to reference the CPU with Intel's Spec# for Maximum Case Temperature, Stepping (which determines Maximum Junction Temperature), Thermal Design Power and Vcore:
http://processorfinder.intel.com/Default.aspx
Intel`s Thermal Specifications:
The thermal specification shown is the maximum case temperature at the maximum Thermal Design Power (TDP) value for that processor. It is measured at the geometric center on the topside of the processor integrated heat spreader.
For processors without integrated heat spreaders such as mobile processors, the thermal specification is referred to as the junction temperature (Tj). The maximum junction temperature is defined by an activation of the processor Intel® Thermal Monitor. The Intel Thermal Monitor's automatic mode is used to indicate that the maximum TJ has been reached.
Section 3: Interpretation
The first part of the spec refers to a single measuring point on the Integrated Heat Spreader (IHS). Since a thermocouple is embedded in the IHS for lab tests only, IHS temperature is replicated using a CPU Case Thermal Diode integrated between the Cores. Maximum Case Temperature is determined by Spec#. The CPU Case Thermal Diode is how Tcase is measured, and is the CPU temperature displayed in BIOS and in the software utility SpeedFan.
The second part of the spec refers to mobile processors without Integrated Heat Spreaders (IHS). Although desktop CPU`s have an IHS, both variants measure the hot spots within each Core using Digital Thermal Sensors (DTS). Maximum Junction Temperatures are determined by Stepping. The Digital Thermal Sensors are how Tjunction is measured, and are the Core temperatures displayed in the software utilities Core Temp and SpeedFan.
Section 4: Thermal Flow
Heat originates within the Cores, where Tjunction sensors are located within the hot spots of each Core. From the bottom of the Cores, heat dissipates throughout the CPU Case, which creates a thermal gradient toward the center of the Die, where the Tcase sensor is located. Heat then dissipates through the socket and motherboard to air inside the computer case. From the top of the Cores, heat dissipates through the Integrated Heat Spreader and CPU cooler to air inside the computer case. Safe and sustainable temperatures are determined by CPU cooling efficiency, computer case cooling efficiency, Ambient temperature, Vcore, clock speed, Stepping and Load. Tjunction is always higher than Tcase, and Tcase is always higher than Ambient.
Section 5: Findings
(A) Depending upon Stepping, the Delta between Tcase and Tjunction is 10c +/- 3 (or) 15c +/- 3.
(B) Tcase is acquired on the CPU Die from the CPU Case Thermal Diode as an analog level, which is converted to a digital value by the super I/O chip on the motherboard. The digital value is Calibrated in BIOS and displayed by temperature software.
(C) Tjunction is acquired within the Cores from Thermal Diodes as analog levels which are converted to digital values by the Digital Thermal Sensors (DTS) within each Core. The digital values are factory Calibrated and displayed by temperature software.
(D) Tcase and Tjunction are both acquired from Thermal Diodes, however, analog to digital (A to D) conversions are executed by different devices in separate locations. BIOS Calibrations, factory DTS Calibrations and temperature software can all be erroneous.
(E) Core Temp, CPU-Z, Crystal CPUID and SpeedFan will be used for Calibrating Tcase and Tjunction at Idle. Prime95 will then be used for Load testing and SpeedFan will be used for temperature monitoring.
Additional Specifications
Ambient Temperature = 22c
Idle to Load Delta Max = 25c
Thermal Diode Accuracy = +/-1c
Tjunction Max = 100c (B3, G0, L2, M0 Stepping)
Tjunction Max = 85c (B2 Stepping)
Section 6: Scale
Safe and sustainable temperatures vary according to Spec# and Stepping. The temperature Scales shown below illustrate the maximum 25c Delta between Idle and Load, and the typical 10c +/- 3 (or) 15c +/- 3 Delta between Tcase and Tjunction among C2Q / C2D variants. Although the Delta between Tcase and Tjunction is constant, these temperatures do not always scale in a precisely linear manner with respect to one another, due to Variables such as Vcore, clock speed, Stepping and Load. Idle at very low Vcore and clock on G0 Stepping may cause Tcase to Tjunction Delta hottest Core to indicate less than 7c, while 100% Workload at very high Vcore and overclock on B2 Stepping at may cause Tcase to Tjunction Delta hottest Core to exceed 18c.
If temperatures increase beyond Hot Scale, then ~ 5c below Tjunction Max, Throttling is activated. The Digital Thermal Sensors (DTS) are used to trigger Intel`s TM1 and TM2 technologies for frequency, multiplier and Vcore Throttling within individual Cores. If Core temperatures increase further to Tjunction Max, then Shutdown occurs. Since Tcase indicates CPU Die temperature only, it is not used for Throttle or Shutdown activation, however, referring to the CPU`s shown below under Scale 1 as examples, Tjunction Throttle temperature is ~ 95c, so Tcase would be ~ 85c, which would far exceed Tcase Max. As Tcase to Tjunction Deltas are constant, Tcase Max is always the limiting specification for temperatures.
Since Intel does not correlate information concerning Tcase and Tjunction into a convenient format, use CPU-Z (see Section 8) to read processor information including the Revision field below the Stepping field, then choose a Scale below which applies to the CPU being tested. Scales are ordered from highest to lowest Tcase Max.
Scale 1: Duo
E4x00: Tcase Max 73c, M0 Stepping, Tjunction Max 100c, Vcore Max 1.325, TDP 65w, Delta 10c
E21x0: Tcase Max 73c, M0 Stepping, Tjunction Max 100c, Vcore Max 1.312, TDP 65w, Delta 10c
E6x50: Tcase Max 72c, G0 Stepping, Tjunction Max 100c, Vcore Max 1.350, TDP 65w, Delta 10c
E6540: Tcase Max 72c, G0 Stepping, Tjunction Max 100c, Vcore Max 1.350, TDP 65w, Delta 10c
-Tcase/Tjunction-
--70--/--80--80-- Hot
--65--/--75--75-- Warm
--60--/--70--70-- Safe
--25--/--35--35-- Cool
Scale 2: Quad
Q6x00: Tcase Max 71c, G0 Stepping, Tjunction Max 100c, Vcore Max 1.372, TDP 95w, Delta 10c
-Tcase/Tjunction-
--70--/--80--80--80--80-- Hot
--65--/--75--75--75--75-- Warm
--60--/--70--70--70--70-- Safe
--25--/--35--35--35--35-- Cool
Scale 3: Quad
QX6x50: Tcase Max 65c, G0 Stepping, Tjunction Max 100c, Vcore Max 1.372, TDP 130w, Delta 10c
QX6700: Tcase Max 65c, B3 Stepping, Tjunction Max 100c, Vcore Max 1.372, TDP 130w, Delta 10c
-Tcase/Tjunction-
--65--/--75--75--75--75-- Hot
--60--/--70--70--70--70-- Warm
--55--/--65--65--65--65-- Safe
--25--/--35--35--35--35-- Cool
Scale 4: Quad
Q6600: Tcase Max 62c, B3 Stepping, Tjunction Max 100c, Vcore Max 1.372, TDP 105w, Delta 10c
-Tcase/Tjunction-
--60--/--70--70--70--70-- Hot
--55--/--65--65--65--65-- Warm
--50--/--60--60--60--60-- Safe
--25--/--35--35--35--35-- Cool
Scale 5: Duo
E6x00: Tcase Max 61c, L2 Stepping, Tjunction Max 100c, Vcore Max 1.325, TDP 65w, Delta 15c
E4x00: Tcase Max 61c, L2 Stepping, Tjunction Max 100c, Vcore Max 1.325, TDP 65w, Delta 15c
E21x0: Tcase Max 61c, L2 Stepping, Tjunction Max 100c, Vcore Max 1.312, TDP 65w, Delta 15c
X6800: Tcase Max 60c, B2 Stepping, Tjunction Max 85c, Vcore Max 1.3525, TDP 75w, Delta 15c
E6x00: Tcase Max 60c, B2 Stepping, Tjunction Max 85c, Vcore Max 1.3525, TDP 65w, Delta 15c
E6x20: Tcase Max 60c, B2 Stepping, Tjunction Max 85c, Vcore Max 1.3525, TDP 65w, Delta 15c
-Tcase/Tjunction-
--60--/--75--75-- Hot
--55--/--70--70-- Warm
--50--/--65--65-- Safe
--25--/--40--40-- Cool
Scale 6: Quad
QX6800: Tcase Max 55c, B3 Stepping, Tjunction Max 100c, Vcore Max 1.372, TDP 130w, Delta 10c
-Tcase/Tjunction-
--55--/--65--65--65--65-- Hot
--50--/--60--60--60--60-- Warm
--45--/--55--55--55--55-- Safe
--25--/--35--35--35--35-- Cool
7: Parameters
(A) Vcore should not exceed 1.5 volts.
(B) NO temperatures can be less than Ambient.
(C) Normal Ambient temperature is specified at 22c.
(D) All temperatures increase as Ambient, clock and Vcore increase.
(E) Tcase Idle is always higher than Ambient, even if less than 0.5c.
(F) Tjunction Idle hottest Core is typically no less than 10c +/- 3 higher than Ambient.
(G) Tcase to Tjunction Delta is ~ 10c on B3 / G0 / M0 Stepping and ~ 15c on B2 / L2 Stepping.
(H) Tjunction Load should not exceed Hot Scale for the CPU being tested.
(I) Tcase Load should not exceed Hot Scale for the CPU being tested.
(J) Tjunction Idle and Load Results are always hottest Core.
(K) Idle to Load Delta should not exceed 25c.
Section 8: Tools
Core Temp, CPU-Z, Crystal CPUID and SpeedFan will be used for Calibrating Tcase and Tjunction at Idle. Prime95 will then be used for Load testing and SpeedFan will provide temperature monitoring. Use the following links to download and install these utilities:
Core Temp 0.95.4 (Beta): http://www.thecoolest.zerobrains.com/CoreTemp
CPU-Z 1.41: http://www.cpuid.com/cpuz.php
Crystal CPUID 4.13.1.340: http://crystalmark.info/download/i [...] ystalCPUID
Prime95 25.4: http://www.mersenneforum.org/showthread.php?t=8981
SpeedFan 4.33 displays Tcase and Tjunction sensors: http://www.almico.com/speedfan.php
Note 1: Core Temp is an excellent utility, however, it has a fundamental flaw in terminology, which creates confusion in the CPU temperature community, by obscuring the distinction between temperature and specification. Core Temp shows Tjunction 85c (or 100c), which is an incorrect term. The proper expression is Tjunction Max 85c (or 100c), which is the term defined by Intel as shown above in the Specifications section, and as represented below:
Tjunction = Core temperature
Tjunction Max = Shutdown
(A) Junction Temperature is a thermal measurement because it scales, thus the term TJ, or Tjunction, which is synonymous with Core temperature.
(B) Maximum Junction Temperature is a specification because it does not scale, thus the term TJ Max, or Tjunction Max, which is synonymous with Shutdown.
(C) ~ 5c below Tjunction Max Throttling is activated. If Tjunction Max is reached, Shutdown occurs, which is either 85c or 100c, and is determined by Stepping.
With this information in mind, it is recommended that Core Temp be used during Calibrations to cross-reference CPU-Z Stepping Revision and SpeedFan Core temperatures.
Note 2: When using Prime95 for the first time, it is necessary to click on Advanced, then click on Round off checking so that errors caused by instabilities will be flagged as they occur. Prime95 will expose insufficient CPU cooling and computer case cooling, or excessive Vcore and overclock. At no other time will a CPU be as heavily loaded, or display higher temperatures, even when OC'd during worst-case loads such as gaming or video editing. Prime95 can be used with SpeedFan to observe CPU temps, while stress testing for system stability. During single threaded gaming and applications, Core 0 typically carries heavier loads and higher temps than other Cores.
Note 3: SpeedFan is very flexible and is the temperature monitoring utility of choice. SpeedFan detects and labels thermal sensors according to various motherboard, chipset and super I/O chip configurations, so the Tcase label can be CPU, Temp 1, Temp 2, or Temp 3. Even if Tcase is labeled as CPU, it is still necessary to confirm the identity of Tcase prior to conducting Calibrations. Run Prime95 and note which SpeedFan temperature scales with an Idle to Load Delta similar to the Cores. This will identify the label corresponding to Tcase. Labels can later be renamed using the Configure button, (see Section 11). If a temperature shows a flame icon, this indicates alarm limits which require adjustment. Use the Configure button to set CPU and Core temp alarms to Safe Scale. If a temperature shows Aux 127, this is simply an unassigned input which can be disabled using the Configure button. CPU`s with Steppings which are Tjunction Max 100c typically require +15c Core Offsets. See Section 11.
Note 4: The software utility (TAT) Thermal Analysis Tool at maximum settings will simulate 100% Thermal Load, which would equate to Prime95 at 114% Workload. This provides the most extreme testing available for CPU and system cooling efficiency. Since TAT is coded to measure Notebook temps, it identifies a C2D as Pentium M. As Notebooks have no Integrated Heat Spreader, thermal scaling differs from desktops CPU`s, so TAT indicates ~ 2c lower, and depending on Variables, temps may be Offset by more than 15c. It is therefore recommended that TAT be used for extreme thermal testing only, and temps regarded as unreliable.
continued below