"What temperature is safe for my processor?"
This question has been asked once too often. I had made alot of research and found all the answers I needed. I still have some details to put out, explaining this more clearly.
Today I called two seperate Intel techs to get correlating answers on all this:
Thermal Monitor (TM): Function activated within the CPU once it has reached the maximum acceptable value at the Tj. At this point it will become active, and start a procedure called "PROCHOT#". It reduces the operating frequency of the CPU to help dissipate accumulated heat. It will remain in this state until it has reached operational temperatures again.
TM.2 (Enhanced TM): If TM fails to cool processor back down to operational temperatures, it will reduce voltages to VID reference voltage. Simultaneously, the CPU will be set to its lowest multiplier.
THERMTRIP#: If TM2 fails to cool CPU to reference Tj temperatures, all power will be cut from all cores. This will remain until temperature is once again restored under specified Tj.
VID: Factory set voltage used when CPU surpasses Tj. If voltages are in excess of VID, they will be lowered to VID in increments allowed by motherboard's BIOS.
Tc (Tcase - Intel labs): Temperature measured at the geometric center of the surface of the CPU. The only way to measure it is to crave a hairline groove in the CPU and apply/solder a hair-sized thermostat probe into the CPU's IHS. This is the way Intel measured the temperature to give the Thermal Specification of each CPU.
Tcase (On-die): This temperature is measured between the cores. It is a sensor included in every Core 2 Duo and Quads. This reading shows up as "CPU Temp" on most programs. It is a little hotter than the Tc from the Intel labs "Thermal Specification"
Tj: Is measured right in the CPU's die, the main silicon area.
The temperature sensors on each core of a Core 2 processor are not very accurate. They produce higher than actual readings to ensure safer operation of TM and TM2 - which in turn almost garantee longevity and reliability of Core 2 CPUs.
Thermal specification is NOT the maximum allowed temperature for safe operation. It is the temperature reached at the specified TDP, in the worst-case ambiant temperature (which is 38C for C2D and C2Q - 39C for C2X and C2QX), using stock HSF. Ambient temperature is measured at 2mm from the blades of the active stock HSF.
This question has been asked once too often. I had made alot of research and found all the answers I needed. I still have some details to put out, explaining this more clearly.
Today I called two seperate Intel techs to get correlating answers on all this:
Thermal Monitor (TM): Function activated within the CPU once it has reached the maximum acceptable value at the Tj. At this point it will become active, and start a procedure called "PROCHOT#". It reduces the operating frequency of the CPU to help dissipate accumulated heat. It will remain in this state until it has reached operational temperatures again.
TM.2 (Enhanced TM): If TM fails to cool processor back down to operational temperatures, it will reduce voltages to VID reference voltage. Simultaneously, the CPU will be set to its lowest multiplier.
THERMTRIP#: If TM2 fails to cool CPU to reference Tj temperatures, all power will be cut from all cores. This will remain until temperature is once again restored under specified Tj.
VID: Factory set voltage used when CPU surpasses Tj. If voltages are in excess of VID, they will be lowered to VID in increments allowed by motherboard's BIOS.
Tc (Tcase - Intel labs): Temperature measured at the geometric center of the surface of the CPU. The only way to measure it is to crave a hairline groove in the CPU and apply/solder a hair-sized thermostat probe into the CPU's IHS. This is the way Intel measured the temperature to give the Thermal Specification of each CPU.
Tcase (On-die): This temperature is measured between the cores. It is a sensor included in every Core 2 Duo and Quads. This reading shows up as "CPU Temp" on most programs. It is a little hotter than the Tc from the Intel labs "Thermal Specification"
Tj: Is measured right in the CPU's die, the main silicon area.
The temperature sensors on each core of a Core 2 processor are not very accurate. They produce higher than actual readings to ensure safer operation of TM and TM2 - which in turn almost garantee longevity and reliability of Core 2 CPUs.
Thermal design power and Themal Specification are used in conjunction with each other as a reference to system builders. Thermal desing power is the amount of power drawn from the PSU, and a requirement for a motherboard. This means that the power consumtion indicated is only a worst-case scenario in which the proper parts are required to handle the power draw.Quoted from Intel's processor finder webpages:
Thermal Design Power: (Also referred to as Thermal Guideline) The maximum amount of heat which a thermal solution must be able to dissipate from the processor so that the processor will operate under normal operating conditions.
Thermal Specification: 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.
Thermal specification is NOT the maximum allowed temperature for safe operation. It is the temperature reached at the specified TDP, in the worst-case ambiant temperature (which is 38C for C2D and C2Q - 39C for C2X and C2QX), using stock HSF. Ambient temperature is measured at 2mm from the blades of the active stock HSF.
More...Sensor on Core 2 Quad processors:
There are 3 sensors per dual core. One on each die called 'DTS' or digital thermal sensor - which are more accurate than I have previously stated; which measure Tjunction (CPU Hot Spots) values. They are set at +/- 1C. But that is only avail on Kentsfield processors.
The Tcase value is measured at a sensor which is located right between the cores. The Tcase value is 15C under Tjunction value.
Tjunction values:
Tjunction Max = 85c (B2 Stepping)
Tjunction Max = 100c (G0, L2, M0, B3 Stepping)
Last edited: