Update : Sep 20, 2020



Intel CPU Temperature Guide 2020

by CompuTronix





Preface ​

Contents



Part 1: How It Works



Section 1 ......................................... Introduction

Section 2 ...................... Ambient Temperature

Section 3 .............................. CPU Temperature

Section 4 ............................. Core Temperature

Section 5 ...................... Package Temperature

Section 6 ...................... Throttle Temperature



Part 2: Sorting It Out



Section 7 ... Specifications and Temperature

Section 8 ............... Overclocking and Voltage

Section 9 ................................ The TIM Problem



Part 3: Methods and Tests



Section 10 ........................... Thermal Test Tools

Section 11 ......................... Thermal Test Basics

Section 12 ..... Thermal Test 100% Workload

Section 13 .......... Thermal Test Minimum Idle



Part 4: Tips and Insights



Section 14 ............... Improving Temperatures

Section 15 .............. Summary and Conclusion

Section 16 .......................................... References





Part 1: How It Works





Section 1 - Introduction ​

I

H

S

Core temperature is considerably higher than CPU temperature due to differences in the proximity of sensors to heat sources.





Figure 1-1 ​ due to differences in the proximity of sensors to heat sources.

T

J

Max

T

Case

Tcase has always been a confusing specification. Here's why:

​

Tcase is not Core temperature.



Tcase is IHS temperature. It's a factory only surface measurement that users can't monitor.

Tjunction is Core temperature. It's measured at the heat sources where temperatures are highest.​





• Tom's Hardware Glossary



Use CPU-Z to identify your processor's specifications:



• CPU-Z





Figure 1-2



You can then look it up at Intel's Product Specifications website:



• Intel Product Specifications





Figure 1-3



For more detailed information, links to Intel’s Datasheets are shown in Section 16 - References.



Note: When asking temperature questions, always provide the following information:



CPU

Cooler

Core speed

Core voltage at load

Load test software

Temperature software

Load & idle Core temperatures

Memory

Motherboard

Graphics Card

Ambient temperature





Section 2 - Ambient Temperature ​ In order to get a clear perspective of processor temperatures, it's important to familiarize yourself with some of the commonly used terms:Use CPU-Z to identify your processor's specifications:You can then look it up at Intel's Product Specifications website:For more detailed information, links to Intel’s Datasheets are shown in Section 16 - References.When asking temperature questions, always provide the following information:CPUCoolerCore speedCore voltage at loadLoad test softwareTemperature softwareLoad & idle Core temperaturesMemoryMotherboardGraphics CardAmbient temperature







Figure 2-1 ​ Here's the temperature conversions and a short scale:

As Ambient temperature increases, thermal headroom and overclocking potential decreases.





Section 3 - CPU Temperature ​

T

Case

I

H

S



Figure 3-1

​

​

Previous Method:

Present Method:

Note :

Section 4 - Core Temperature ​

T

Junction

D

T

S



Figure 4-1 ​

Core temperature is the standard for processor thermal measurement.

​

Core temperatures respond instantly to changes in load.​





Core temperatures above 85 °C are not recommended .



Core temperatures below 80 °C are ideal.





Figure 4-2



Core temperatures increase and decrease with Ambient temperature.



Idle temperatures below 25°C are generally due to Ambient temperatures below 22°C.

​ Here's the nominal operating range for Core temperature:Idle temperatures below 25°C are generally due to Ambient temperatures below 22°C.





Here’s a list of variables that affect Core temperature:



Ambient temperature

CPU Cooler

Fan speed

Pump speed

Thermal Interface Material

IHS / Cooler flatness

Core count

Core speed

Core voltage

BIOS updates

Turbo Boost

Hyper-Threading

Instruction Sets

Thermal Design Power

Memory

Case design

Cable management

Computer location

Ventilation

GPU cooler type

SLI / CrossFire

Dust



For more information see Section 14 - Improving Temperatures.





Section 5 - Package Temperature ​ For monitoring Core Temperature, a simple and accurate utility that's frequently updated is Core Temp Here’s a list of variables that affect Core temperature:Ambient temperatureCPU CoolerFan speedPump speedThermal Interface MaterialIHS / Cooler flatnessCore countCore speedCore voltageBIOS updatesTurbo BoostHyper-ThreadingInstruction SetsThermal Design PowerMemoryCase designCable managementComputer locationVentilationGPU cooler typeSLI / CrossFireDustFor more information see Section 14 - Improving Temperatures.

Section 6 - Throttle Temperature ​

T

J

Max

T

D

P



Core i



10th Generation 14 nanometer i9-10900K / i7-10700K (TDP 125W)

9th Generation 14 nanometer i9-9900K / i7-9700K (TDP 95W)

8th Generation 14 nanometer i7-8700K / i5-8600K (TDP 95W)

7th Generation 14 nanometer i7-7700K / i5-7600K (TDP 91W)

6th Generation 14 nanometer i7-6700K / i5-6600K (TDP 91W)

Tj Max (Throttle temperature) 100 °C



5th Generation 14 nanometer i7-5775C / i5-5675C (TDP 65W)

Tj Max (Throttle temperature) 96 °C



4th Generation 22 nanometer i7-4790K / i5-4690K (TDP 88W)

4th Generation 22 nanometer i7-4770K / i5-4670K (TDP 84W)

Tj Max (Throttle temperature) 100 °C



3rd Generation 22 nanometer i7-3770K / i5-3570K (TDP 77W)

Tj Max (Throttle temperature) 105 °C



2nd Generation 32 nanometer i7-2700K / i5-2550K (TDP 95W)

Tj Max (Throttle temperature) 98 °C



1st Generation 45 nanometer i7-880 / i5-760 (TDP 95W)

1st Generation 45 nanometer i7-960 D0 (TDP 130W)

Tj Max (Throttle temperature) 100 °C



Core 2



Core 2 45 nanometer Q9650 E0 / Q9550 E0 (TDP 95W)

Core 2 65 nanometer Q6700 G0 / Q6600 G0 (TDP 95W)

Tj Max (Throttle temperature) 100 °C​

Note :

Part 2: Sorting It Out





Section 7 - Specifications and Temperature

​

Note :

• TDP specifications

• Tcase specifications

• Intel Stock Coolers



Compared below are a few processor / stock cooler combinations with respect to TDP and Tcase specifications:



Example 1 ...... i7-2600K 95 Watts TDP / Cooler 95 Watts TDP / Tcase 72 °C

Example 2 ...... i7-3770K 77 Watts TDP / Cooler 95 Watts TDP / Tcase 67 °C

Example 3 ... i7-6700K 91 Watts TDP / Cooler 130 Watts TDP / Tcase 64 °C



Note the 2600K and 3770K use the same 95 Watt cooler. Here's how the examples look on a graph:





Figure 7-1

​ Compared below are a few processor / stock cooler combinations with respect to TDP and Tcase specifications:Example 1 ...... i7-2600KWatts TDP / CoolerWatts TDP / Tcase°CExample 2 ...... i7-3770KWatts TDP / CoolerWatts TDP / Tcase°CExample 3 ... i7-6700KWatts TDP / CoolerWatts TDP / Tcase°CNote the 2600K and 3770K use the sameWatt cooler. Here's how the examples look on a graph:

Tcase is irrelevant







Figure 7-2 ​ Tj Max specifications are shown in the Datasheets in Section 16 - References, and in the monitoring utility Core Temp

• Tj Max specifications

100

212



Figure 7-3

​

Core temperatures above

85

°C are not recommended

Section 8 - Overclocking and Voltage ​

• Overclocking is always limited by two factors; voltage and temperature.​

not







Figure 8-1 ​ Here's the Maximum Recommended Vcore per Microarchitecture from 14 to 65 nanometers since 2006:

Extreme





Figure 8-2 ​

permanent







Figure 8-3

​ Here's an example of a Core Voltage / Frequency Curve:

80

80

• CPU overclocking guide and tutorial for beginners





Section 9 - The TIM Problem ​

T

I

M



Figure 9-1

​

Beware that delidding will void your warranty, and if not performed carefully, can damage or destroy your processor.



Rather than delid using the risky razor blade or vice methods, you can safely delid with a "delidding tool":



der8auer Delid Die Mate 2

Dr. Delid

Rockit 88​ , and if not performed carefully, can damage or destroy your processor.Rather than delid using the risky razor blade or vice methods, you can safely delid with a "delidding tool":

Note 1 :





IHS to Die - Soldered CPUs







IHS to Die - Liquid Metal



Thermal Grizzly Conductonaut ........... 73.0 W/mk

CoolLaboratory Liquid Extreme ........... 41.0 W/mk

CoolLaboratory Liquid Ultra .................. 38.4 W/mk

CoolLaboratory Liquid Pro ..................... 32.6 W/mk



IHS to Cooler - Paste



Thermal Grizzly Kryonaut Extreme ... 14.2 W/mk

Arctic Silver 5 .................................................. 9.0 W/mk

Arctic Cooling MX4 ...................................... 8.5 W/mk

Gelid Solutions GC-Extreme ...................... 8.5 W/mk

​ For comparison, here’s a short list of TIM in order of thermal conductivity:IHS to Die - Indium .............................................................. 81.8 W/mkIHS to Die -73.0 W/mkCoolLaboratory Liquid Extreme ........... 41.0 W/mkCoolLaboratory Liquid Ultra .................. 38.4 W/mkCoolLaboratory Liquid Pro.................. 32.6 W/mkIHS to Cooler -14.2 W/mkArctic Silver 5......................................... 9.0 W/mkArctic Cooling MX4....................... 8.5 W/mkGelid Solutions GC-Extreme ...................... 8.5 W/mk



10th Generation ............... Comet Lake - 5 to 12°C

9th Generation ... Coffee Lake Refresh - 3 to 7°C

8th Generation .............. Coffee Lake - 12 to 25°C

7th Generation .................. Kaby Lake - 12 to 25°C

6th Generation .......................... Skylake - 7 to 20°C

5th Generation ..................... Broadwell - 8 to 18°C

4th Generation ........... Devil's Canyon - 7 to 15°C

4th Generation ....................... Haswell - 10 to 25°C

3rd Generation ................... Ivy Bridge - 10 to 25°C

​







Figure 9-2

​ Here's how "The TIM Problem" looks on a graph:

Video 9-1



Core temperatures and IHS temperature converge at idle and diverge as load increases. Here’s how solder and paste differ between idle and 100% workload:





Figure 9-3 ​ Core temperatures and IHS temperature converge at idle and diverge as load increases. Here’s how solder and paste differ between idle and 100% workload:

Note 2 :

The topic of processor temperatures can be very confusing. Conflicting opinions based on misconceptions concerning terminology, specifications and testing leaves users uncertain of how to properly check cooling performance. This Guide provides an understanding of standards, specifications, thermal relationships and test methods so temperatures can be properly tested and compared. It is frequently updated and supports X-Series, Extreme, Core i, Core 2, Pentium and Celeron Desktop processors running Windows Operating Systems.Intel Desktop processors have temperatures for each "Core" and a temperature for the entire "CPU". Core temperatures are measured at the heat sources near the transistor "Junctions" deep inside each Core where temperatures are highest. CPU temperature is instead a single measurement centered on the external surface of the CPUs "Case" or "IHS" (ntegratedeatpreader) where the cooler is seated.Intel Desktop processors also have two Thermal Specifications. For Core temperature it's "Tjunction" which is also called "Tj Max" (emperatureunctionimum) or “Throttle” temperature. For CPU temperature it's "Tcase" (emperature) which is IHS temperature.Both Thermal Specifications are shown on Intel’s "Datasheets", which are detailed technical documents. However, Intel's "Product Specifications" website is a quick reference that only shows Tjunction for 7th Generation and later processors,Tcase for 6th Generation and earlier.When users of 6th Generation and earlier processors see their Thermal Specification on Intel’s Product Specifications website, most don’t realize what Tcase actually means. As there are numerous software utilities for monitoring Core temperature, usersTcase must be maximumtemperature. This is a basic misconception which has persisted since 2006.Since users can monitor Core temperatures but not IHS temperature, Core temperature is the standard for thermal measurement. Accordingly, theThermal Specification is Tjunction;Tcase. Unfortunately, Intel has no documentation that describes the relationships between specifications and temperatures in a practical sense, so further explanations are given throughout the Guide.Also called "room" temperature, this is the temperature measured at your computer's air intake.isor, which isroom temperature. Ambient temperature is afor Intel’s Thermal Specifications. Knowing your Ambient temperature is important because. Use a trusted analog, digital or infrared (IR) thermometer to measure Ambient temperature.When you power up your rig from a cold start, all components are at Ambient, so temperatures can only increase. With conventional air or liquid cooling,Also called "Tcase" (emperature), this is atemperature measured on the external surface of the IHS (ntegratedeatpreader) using. Fortesting only, a groove is cut into the surface of the IHS where a "thermocouple" sensor is embedded at the center. The processor is installed, the stock cooler is seated, the thermocouple is connected to monitoring devices, and the temperature is then tested under carefully controlled conditions., so one of two different methods are used to display “CPU” temperature in BIOS and in monitoring utilities.Core 2 Socket 775 and Core i 1st Generation Socket 1366 processors have a single Analog Thermal Diode below the Cores to "" for a thermocouple sensor. The Analog value is converted to Digital (A to D) by the motherboard's Super I/O (Input / Output) chip, then is calibrated to look-up tables coded into BIOS. The monitoring utility provided by the motherboard manufacturer on your Driver CD displays “CPU” temperature in Windows.Core i Sockets 115x, 1200 and Extreme / X-Series Socket 20xx processors dohave an Analog Thermal Diode, but instead "" the "hottest Core" for "CPU" temperature, which is a contradiction in terms that can be confusing. Nonetheless, this is the temperature shown in BIOS, and on some recent motherboards is shown on the two digit "debug" display. The monitoring utility provided by the motherboard manufacturer on your Driver DVD displays “CPU” temperature in Windows, but is actually the "hottest Core".Regardless of the Method used, CPU temperature in BIOS is higher than in Windows at minimum idle, because BIOS boots the processor without power saving features and at higher Core voltages to ensure that it will initialize under any conditions.The term “CPU” temperature is commonly misused as aterm forprocessor temperatures. Unfortunately, this blurs the distinctions between CPU temperature and Core temperature. Surprisingly, there are numerous instances where Intel contradicts their own terms. For example, Intel Extreme Tuning Utility software (IETU) and the Product Specifications website both have inconsistencies with the Datasheets, which use proper terminology.Also called "Tjunction" (emperature), this is the temperature measured at the heat sources near the transistor “Junctions” inside each Core by individualigitalhermalensors (DTS).Since the Digital Thermal Sensors (DTS) are located deep within the Cores where temperatures are highest, and Tcase is a factory measurement on the Integrated Heat Spreader (IHS) where temperatures are lower, there's a temperature difference between DTS and IHS locations. At 100% workload, the difference can range from 5 to 25°C which varies according to processor Generation. The significance of these differences is explained in Section 9 - The TIM Problem.Intel's specification for DTS accuracy is +/- 5°C. Although sensors are factory calibrated, deviations between the highest and lowest Cores can be up to 10°C. Sensors tend to be more accurate at high temperatures, but due to calibration issues such as linearity, slope and range,Intel’s specification for DTS response time is 256 milliseconds, or about 1/4th of a second. Since Windows has dozens of Processes and Services running in the background, it’sto see rapid and random Core temperature “spikes” or fluctuations, especially during the first few minutes after startup.software activity will show some percentage of CPU Utilization in Windows Task Manager, where unnecessary Tray items, Startups, Processes and Services that contribute to excessive spiking can be disabled. For details see Section 13, Note 1.Highest Core temperatures occur during stress tests or heavy rendering and transcoding, but are lower during less processor intensive apps. Gamingaverages around 55 to 60°C, yet can range from 40 to 75°C, depending on how different games allocate CPU / GPU workloads, as well as differences in overall cooling performance and Ambient temperature.. In some utilities, "Package" temperature is synonymous with "CPU" temperature, where both correspond to the same sensor and display the same temperature.Package temperature may intermittently deviate +/- a few degrees from the hottest Core due to a slight difference in sample timing.Package temperature is shown in more detailed utilities such as Hardware Info . Package temperature can be influenced by Intel's on-Die IGPU (Integrated Graphics Processor Unit).Also called "Tj Max" (emperatureunctionimum), this is the Thermal Specification that defines the Core temperatureat which the processor will Throttle (reduce Core speed and voltage) to safeguard against thermal damage. Processors that reach Throttle temperature can cause momentary hesitations in applications and frame stuttering in games.Throttle temperatures are shown below for several "Flagship" processors and their popular mainstream variants, including " TDP " (hermalesignower), which is expressed in Watts (W).In 2006, early Core 2 processors used DTS sensors for Throttle protection only; not for Core temperatures. Instead, CPU temperature (less accurate) was monitored using the Analog Thermal Diode. Utility developers soon discovered how to read Tj Max and monitor Core temperatures. Intel later disclosed Tj Max values in the Datasheets, and discontinued the Analog Thermal Diode after 45 nanometer processors. For 7th Generation and later, Intel changed the Product Specifications website in 2016 from Tcase to Tjunction (Tj Max).The previous Sections explained Intel’s specifications concerning how temperatures are measured. This Section focuses on how Thermal Design Power (TDP) relates to Thermal Specifications, and why Tcase and Tj Max "face values" are inconsistent with sensible real-world Core temperatures.With respect to terminology, Intel’s Product Specifications website incorrectly shows either “Tcase” or “Tjunction” as. In that context, both are technically improper terms. The Datasheets, which use proper terminology, instead show “Tcase” and “Tj”. For the record, “Tcase” is a, while “Tcase” is IHS. Correspondingly, “Tj” is a, while “Tjunction” is Coreare expressed in Watts, which is Power that's dissipated as heat. The key word in “ThermalPower” is. Processors of the sameare simultaneously fabricated on the same silicon wafer, but some have flaws. The best are “ binned " as “Flagship” unlocked processors with all features enabled. Those with more flaws either have Cores, Cache , Hyper-Threading, Integrated Graphics or certain Instruction Sets disabled, and may be locked or binned at slower Core speeds For example, although processors of the same, Generation and Core count may share the same ThermalPower, variants Hyper-Threading and those which run at slower Core speeds consume less Power and may not reach or exceed TDP unless overclocked. Higher Core temperatures are most prevalent among unlocked processors with higher TDP, higher Core speeds, Hyper-Threading and 4 Cores or more, which all require higher TDP aftermarket cooling, especially when overclocked.areIHS temperature measurements that users can't monitor. Tcase is not a thermal, but is instead a thermalbased on processor TDP and stock cooler TDP. Coolers and CPUs ofTDP values are often packaged together. Several Generations of Quad Core CPUs at 77, 84, 88 and 95 Watts were packaged with a universal 95 Watt cooler. But for 6th through 10th Generation 91, 95 and 125 Watt processors, Intel's specified 130 Watt stock cooler is sold separately.The higher the cooler TDP is from the processor TDP, the lower the Tcase specification. Likewise, when the stock cooler is replaced with a higher TDP aftermarket cooler, IHS temperature (Tcase) as well as Core temperatures are lower. This means. In the examples above, the higher Tcase value of the 2600K suggests that it has a higher thermal tolerance than the 6700K, which is, as the 6700K has a higher Throttle temperature.While TcaseTjunction (Tj Max) specifications are both shown in the Datasheets, the Product Specifications website only shows Tjunction for 7th Generation and later,Tcase for 6th Generation and earlier. For example, the 6th Generation 6700K and the 7th Generation 7700K share the samewithTcase and Tj Max specifications, but the processor's Generation determines which of the two Thermal Specifications is shown on the website.Intel’s move away from using Tcase on their website synchronizes Desktop and Mobile Thermal Specifications. Mobile (laptop) processors don’t have an IHS, so they don’t have Tcase specifications; only Tj Max. Although users can’t monitor IHS temperature, Intel's intended purpose for providing Tcase specifications is primarily for developers of aftermarket cooling solutions. So from Core 2 processors in 2006 to today's Core i processors, theThermal Specification hasbeen Tj Max;Tcase. For end users, this meansalso vary with TDP specifications. Certain low TDP variants may Throttle below 90°C, while for others, the highest Tj Max value is 105°C. However, some motherboards for 9th and 10th Generation processors violate TJ Max by allowing users to increase Intel's thermal limit from°C (°F) where most processors Throttle, to 115°C which can damage your CPU. Nevertheless, you should not run your processor near its thermal limit, just as common sense tells you not to drive a vehicle with the temperature gauge on red.If your hottest Core is near its specified Tj Max Throttle temperature, then your CPU is already too hot. The consensus among well informed and highly experienced reviewers, system builders and expert overclockers, is that it's prudent to observe a reasonable thermal margin below Throttle temperature for ultimate stability, performance and longevity. So regardless of environmental conditions, hardware configurations, software workloads or any other variables,No two processors are identical; each is unique in voltage tolerance, thermal behavior and overclocking potential, which is often referred to as the "silicon lottery".As Core speed (MHz) increases, Core voltage (Vcore) automatically increases to maintain stability. However, it'srecommended to overclock using “Auto” BIOS settings, motherboard features or software utilities, as significantly more Vcore than necessary is applied to maintain stability, which needlessly increases Power and heat. It's insteadrecommended to use only "manual" Vcore in BIOS. Most overclocking guides explain how. Since overclocked processors can run more than 50% above rated TDP,Each Microarchitecture has a “Maximum Recommended Vcore”. For example, it’s important to point out that 22 nanometer 3rd and 4th Generation processors willtolerate the higher Core voltages of other Microarchitectures.We know that over time, excessive voltage and heat damages electronics, so when using manual Vcore settings in BIOS, excessive Core voltage and Core temperature can cause accelerated "". Processors have multiple layers of hundreds of millions of microscopicscale components. Electromigration erodes fragile circuit pathways and transistor junctions which results in theof overclock stability, and thus performance.Although your initial overclock may be stable, degradation doesn't appear until later, when increasingly frequent blue-screen crashes indicate a progressive loss of stability. The more excessive the levels of voltage and heat and the longer they're sustained determines how long until transistor degradation destabilizes your overclock. Decreasing overclock and Vcore may temporarily restore stability and slow the rate of degradation.overvolting can cause degradation in minutes, but a sensible overclock remains stable for years.Each Microarchitecture also has a " Degradation Curve ". As a rule, CPUs are more susceptible to electromigration and degradation with each Die-shrink. However, the exception to the rule is Intel's 14 nanometer Microarchitecture, where advances in FinFET transistor technology have improved voltage tolerance.Here's how the Degradation Curves correspond to Maximum Recommended Vcore for 22 nanometer 3rd and 4th Generation, which differs from 14 nanometer 5th through 10th Generation:Degradation Curves are relative to the term “” which is expressed in millivolts (mv). Users can not monitor Vt Shift. With respect to overclocking and overvolting, Vt Shift basically represents the potential forloss of normal transistor performance. Excessively high Core voltage drives excessively high Power consumption and Core temperatures, all of which contribute to gradual Vt Shift over time. Core voltages that impose high Vt Shift values arerecommended.To achieve the highest overclock, keep in mind that for your final 100 MHz increase, a corresponding increase in Core voltage of about 50 millivolts (0.050) is needed to maintain stability. If 70 millivolts (0.070) or more is needed for the next stable 100 MHz increase, it means you're attempting to overclock your processor beyond its capability. All processors reach a limit where an additional increase in Core voltage willstabilize another 100 MHz increase in Frequency.With high-end cooling you might reach your Maximum Recommended Vcore limit before you reach the ideal Core temperature limit at°C. With low-end cooling you’ll reach°C before your Vcore limit. Regardless, whichever overclocking limit you reach first is where you should stop. Thermal testing is explained in Sections 10 through 12.Remember to keep overclocking in perspective. For example, the difference between 4.5 and 4.6 GHz is less than 2.3%, which has no noticeable impact on overall system performance. It simply isn’t worth pushing your processor beyond recommended Core voltage and Core temperature limits just to squeeze out another 100 MHz.hermalnterfaceaterial or “TIM” (thermal compound) facilitates better heat transfer from one surface to another. TIM can refer to either paste (pTIM) or solder (sTIM) or liquid metal. In 3rd Generation mainstream processors, Intel stopped using solder and instead started using paste between the “Die” and IHS, which resulted in higher Core temperatures, thus creating "The TIM Problem”.In Core 2 and Core i 1st and 2nd Generation, as well as 9th and 10th Generation "K" and "X" processors, a specially formulated solder that contains " Indium " is used between the Die and IHS for good thermal conductivity. However, when paste is used between the Die and IHS, thermal conductivity is comparatively poor. This is primarily why 3rd through 8th Generation mainstream processors are more difficult to cool.Additionally, 3rd through 8th Generation are "small Die" processors with significantly less surface area in contact with the IHS to transfer heat than 2nd Generation and earlier "large Die" processors. They also have more transistors densely packed into their small Die and consequently are more thermally sensitive to small increases in Vcore and Core speed.In 3rd through 8th Generation mainstream processors, the sealant between the Substrate and IHS tends to be slightly too thick, which creates unwanted space between the Die and IHS. During assembly, this can also cause the paste to compress unevenly. And as paste has comparatively poor thermal conductivity, the effect is higher Core temperatures, with some processors showing wide deviations between Cores, or one Core which runs much hotter than its neighbors.This encourages some overclockers to " delid " or remove their processor's IHS and replace Intel's pTIM with “liquid metal”, which has good thermal conductivity much closer to Indium solder. Typical results are dramatically lower Core temperatures with less deviation between Cores.Delidding requires that you useliquid metal TIM between the Die and IHS. Paste (pTIM) will fail in a relatively brief period of time. Due to thermal cycling, a process known as “pump-out” will expel pTIM from between the Die and IHS, whereas liquid metal is very resistant to pump-out. Although Intel's pTIM is formulated to resist pump-out, it still degrades over time, losing its thermal bond with the Die. The most recommended liquid metal TIM is Thermal Grizzly Conductonaut. Silicon Lottery is a company that tests, bins and sells overclocked, delidded "K" CPUs. They also offer professional delidding services, and give the following figures on how much Core temperatures at 100% workload are improved by delidding:Except for 9th and 10th Generation, Core temperatures on processors with solder between the Die and IHS are typically within about 5°C above IHS temperature, which indicates good thermal conductivity. However, Core temperatures on processors with paste between the Die and IHS can vary up to 25°C above IHS temperature, which indicates poor thermal conductivity and inconsistent uniformity.Although 9th and 10th Generations use sTIM, the solder is much thicker than earlier soldered processors, which decreases thermal conductivity. Additionally, the Die in 9th Generation is twice as thick as earlier Generations, which further decreases thermal conductivity. Here’s a detailed explanation by Mechatronics Engineer, Roman “” Hartung:Thermal behavior is relatively uncompromised at idle due to low Power dissipation. But as workload approaches 100%, poor thermal conductivity among processors with paste becomes apparent. Moreover, as Intel's pTIM degrades over time, 3rd through 6th Generation 22 and 14 nanometer processors, (launched 2012 through 2015), may no longer cool as well as when new. Delidding restores and upgrades thermal performance similar to that of earlier soldered processors.Intel useswithfor testing and developing specifications.