jo3ypgaming,
On behalf of Tom's Moderator Team, welcome aboard!
Intel’s specification for Digital Thermal Sensor (DTS) accuracy is +/- 5°C. This means deviations between the highest and lowest Cores can be up to 10°C. Deviations on processors that have an uneven application of TIM might exceed 10°C by several degrees.
Since you've re-TIM'd multiple times, your
external is not the problem; it's likely the
internal TIM between the Die and the IHS.
3rd through 8th Generation mainstream processors use "TIM" (
Thermal
Interface
Material) between the Die and IHS, which has relatively poor thermal conductivity. "Indium" solder, which has good thermal conductivity, was instead used in 2nd Generation and earlier processors, and is once again being used in 9th Generation.
Since the material that seals the perimeter of the IHS to the Substrate is slightly too thick, this tends to create space between the Die and IHS, which can also cause the TIM to compress unevenly. The effect is high Core temperatures, with some processors showing
wide deviations between Cores, or one Core which runs much hotter or cooler than it's neighbors.
This has encouraged some overclockers 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.
You can safely delid with 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 overclocked, delidded "K" CPU's. They also offer professional delidding services, and give 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 - 12° to 25°C
6th Generation ... Skylake - 7°C to 20°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
To illustrate the scope of this problem, thermal characteristics among soldered and TIM’d processors are compared below:
Core temperatures on processors with Indium solder between the Die and IHS are typically within 5°C above IHS temperature, which indicates good thermal conductivity. However, Core temperatures on processors with TIM between the Die and IHS vary up to 25°C above IHS temperature, which indicates poor thermal conductivity and uniformity.
Note 1: Although 9th Generation is soldered, the Die and solder are both considerably thicker, which adversely affects thermal conductivity. Here’s a detailed explanation by Mechatronics Engineer Roman “der8auer” Hartung -
https://www.youtube.com/watch?v=r5Doo-zgyQs
Note 2: Intel uses
engineering samples with
soldered Integrated Heat Spreaders for testing and developing specifications.
Core temperatures and IHS temperature converge at idle and diverge as load increases. Here’s how soldered and TIM’d processors differ between idle and 100% workload:
Thermal behavior is relatively uncompromised at idle due to low Power dissipation. But as workload approaches 100%, poor thermal conductivity among TIM’d processors becomes apparent. Moreover,
as Intel's TIM degrades over time, some 3rd and 4th Generation 22 nanometer processors, (launched 2012 through 2014), may no longer cool as well as when new. Delidding restores and upgrades thermal performance similar to that of soldered processors.
Unfortunately, the only way to correct the thermal deviations between Cores on your 4790K is to delid. If you don't want to attempt it yourself, then you can send it to Silicon Lottery. They do an excellent, professional job for a fair price and warranty the results.
Also, you might want to read this:
Intel Temperature Guide -
http://www.tomshardware.com/forum/id-1800828/intel-temperature-guide.html
Once again, welcome aboard!
CT
Facebook
Twitter
Instagram