The TIM Problem
Core i 3rd through 8th Generation processors are very sensitive to small increases in voltage and frequency, and are more difficult to cool than earlier processors, so
high-end air or liquid cooling is crucial. Here's why:
(1) The 3rd through 8th Generation processors are "small Die" processors which have significantly less surface area in contact with the Integrated Heat Spreader (IHS) than "large Die" 2nd Generation and earlier processors.
(2) 3rd through 8th Generation processors have more transistors densely packed into their small Die than large Die 2nd Generation and earlier processors.
(3) 3rd through 8th Generation mainstream processors use
Thermal
Interface
Material (TIM) between the Die and IHS. "Indium" solder, which has good thermal conductivity, was instead used in 2nd Generation and earlier mainstream Desktop processors.
Since the material which seals the perimeter of the IHS to the Substrate is slightly too thick, this tends to increase the space between the Die and IHS, which can also cause the TIM to compress unevenly. The effect is increased Core temperatures, with some processors showing wide deviations between Cores, or one Core which runs much hotter than it's neighbors.
This has encouraged some users to "delid" or remove their processor's IHS and replace Intel's TIM with liquid metal TIM, allowing thermal conductivity much closer to Indium solder. Typical results are dramatically lower Core temperatures with less deviation between Cores.
Beware that delidding will void your warranty, and if not performed carefully, can damage or destroy your processor.
Instead of manually delidding by hand, you can safely delid by using a "delidding tool" such as the Rockit 88 - https://rockitcool.myshopify.com/
Silicon Lottery -
https://siliconlottery.com/collections/all/products/delid - is a company that tests, bins and sells delidded "K" CPU's. They also offer professional delidding services, so you can simply send in your CPU, and they'll delid it for you.
To illustrate how bad Intel's TIM problem really is, Silicon Lottery gives the following figures on how much Core temperatures at 100% workload are improved by delidding:
8th Generation ... Coffee Lake - 12° to 25°C
7th Generation ... Kaby Lake X - 12° to 25°C
7th Generation ... Kaby Lake - 12° to 25°C
6th Generation ... Skylake X - 7°C to 20°C
6th Generation ... Skylake - 8°C to 18°C
5th Generation ... Broadwell - 8°C to 18°C
4th Generation ... Devil's Canyon - 7°C to 15°C
4th Generation ... Haswell - 10°C to 25°C
3rd Generation ... Ivy Bridge - 10°C to 25°C
Shown below are the thermal characteristics between different Generations of soldered and TIM’d processors:
Core temperatures on earlier processors with Indium solder between the Die and IHS are consistently within 5°C above IHS temperature, which indicates good thermal conductivity. However, Core temperatures on later Generations with TIM between the Die and IHS are up to 25°C above IHS temperature, which indicates relatively poor thermal conductivity and uniformity.
Sloppymop,
Delidding has, by far, the most profound impact on decreasing Core temperatures. Ever since Intel began using TIM with their 3rd Generation Ivy Bridge processors, I've been delidding every i7 and i5 "K" processor in my builds, as well as my personal rigs. The results are always very impressive and convincing.
You might want to consider sending you CPU to Silicon Lottery. They do a great job and warranty their work. You can also have them "bin" your CPU, which means they test it for maximum stable overclock, and provide you with the BIOS settings to do it yourself. Check out their website: Silicon Lottery -
https://siliconlottery.com/collections/all/products/delid
CT