Thermal Interface and Extreme Overclocking

(with Alva Jonathan)

One of the big questions surrounding the new CPU is if Intel has decided to make changes to the way the CPU and the heatspreader make contact. The best way to make contact is to use an Indium-Tin solder, or a liquid metal, to ensure that the thermal load from the CPU is taken directly to the CPU cooler. The cheaper method (but more reliable method) is with a thermal paste, which is more resilient to thermal expansion coefficients over the lifecycle of the processor. In a perfect world, we'd expect the highest performance processors to use the solder method while cheaper processors can use a thermal paste. However Intel has been making its processors solely with thermal paste of late, causing extreme enthusiasts to resort to delidding and adjusting the thermal paste with liquid metal. AMD uses thermal paste in its APUs, and we did a delidding guide a few weeks back:

Delidding The AMD Ryzen 5 2400G APU: How To Guide and Results

The Intel method is mostly similar. However, the question for this review was if Intel would change from a thermal paste as used on the Core i7-8700K to a more overclocking and thermally friendly solder for the Core i7-8086K. The idea is that if Intel is geared towards enthusiasts, solder should be used, right?

Making It Possible

For this page, we are extremely thankful to Alva Jonathan, aka ‘Lucky_n00b’, a fellow overclocker and journalist for Jagat Review. I'm known Alva for almost 10 years, and like me, he also purchased his Core i7-8086K during Computex this week, except he went the full beans with delidding and liquid nitrogen. He is allowing us to share his results with our audience, so a big thank you to Alva!


Alva does some impressive overclocking coverage on all the new platforms at Jagat Review (in Indonesian), as well as doing exceeding well at overclocking competitions around the world. This week he scored third place at G.Skill’s live overclocking event at Computex, scoring some nice hardware and a cash prize.

Alva’s Core i7-8086K OC and analysis can be found here (in Indonesian).

Opening Up The Chip

Suffice to say, Intel made zero changes to the thermal interface on the Core i7-8086K. It is completely identical to the Core i7-8700K, using the same thermal goop as in previous generations of chips. For current Coffee Lake processors, removing the thermal goop and replacing it with a liquid metal implementation is generally good for lowering temperatures from 5-15C (depending on the quality of the application) or gaining another 100-300 MHz depending on the voltage response of the chip.

Alva recommends only delidding the processor for more frequency or better thermals if you intended to use more than 1.30 volts through the CPU. At this voltage, with a good ambient cooler, users will start to hit around 80 C when running the CPU at full load (we can confirm, our sample was similar), which is a good point for anyone considering a delid.

With his CPU, Alva achieved 5.0 GHz at 1.20 volts, which was stable enough to run CineBench R15 for a score of 1627 (compared to 1424 at stock with fast memory). The CPU also managed 5.2 GHz at 1.35 volts for a few more points at 1692. He used KingpinCooling KPX as the replacement thermal interface material.

Going Beyond with Liquid Nitrogen (LN2)

Extreme overclocking is an interesting pastime to participate in, however for the users on the extreme edge of the sport, every MHz counts. Not only for cooling but systems are physically modified to add better power delivery or to adjust voltages manually rather than through software. For those that can, it creates a thrill or two.

In Alva’s testing notes, he started with MSI’s Z370 Godlike Gaming motherboard prepped for sub-zero cooling, and used a heavy LN2 copper pot to manage temperatures with the liquid nitrogen. After bring the system down to -100C, he booted with BIOS settings such that the CPU was at 6.0 GHz (60x100), with an uncore of 5.0 GHz and a CPU voltage of 1.70 volts. Don’t try this without sub-zero cooling (!). Other voltages were as follows:

  • SA/IO Voltage: 1.35 V
  • DMI Voltage: 1.80 V
  • CPU PLL Voltage: 2.20 V
  • CPU PLL OC Voltage 2.20 V
  • CPU ST Voltage: 1.35 V
  • CPU ST V6 Voltage: 1.35 V

The CPU was kept in its full 6C/12T mode.

After booting into the OS, MSI Command Center Lite was used to adjust the processor variables (multiplier, base clock, voltage) in real time. The system was cooled down further to its limit, known as ‘full-pot’ liquid nitrogen benchmarking, and the multiplier was raised to find the absolute processor frequency limit for a no-holds barred validation.

The final result? 7309 MHz:

In general, Skylake-based processors tend to see peak liquid nitrogen frequencies around 7.1-7.4 GHz, so this new processor is nothing out of the ordinary. Alva said that he was quite happy with this single chip, however he will need to test a few more to see exactly where if there is variation in the wafer/batch from Intel. When Alva posts his full sub-zero overclocking article, I will link to it here.

Edit: Here is Alva's article -

Intel Core i7-8086K Review Ambient Overclocking and Power Scaling Analysis
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  • peevee - Monday, June 11, 2018 - link

    8086 being slower than 8700 just indicates an error in your methodology.
    For example, one has updated microcode for exploits and another does not.
  • TheinsanegamerN - Monday, June 18, 2018 - link

    OOORrrrr....its a different motherboard, not the usual test bed. The motherboard used for this is an asrock board, which explains the difference in performance.
  • Memo.Ray - Monday, June 11, 2018 - link

    As I mentioned in my comment in the other article a couple of days ago:

    Intel managed to give away 8086 "binned" 8700K (AKA 8086K) and still make some money on top of it. win-win situation :D
  • Xenphor - Monday, June 11, 2018 - link

    How did they get such a lower score on the Dolphin benchmark with a 5ghz overclock on the 8086k? Isn't the benchmark single core only and considering the 8086 already turbos to 5ghz on a single core, why would there be that much of a difference? I tried it on my 8700k at 5ghz and only get a score of about 265-270 with 2666mhz ram.
  • Ian Cutress - Monday, June 11, 2018 - link

    The 5.0 GHz turbo, at stock, doesn't kick in that often. Depends on how the software sets its own affinity, and most do not. This is the danger with only single core turbo - with all the modern software in the background, even with Windows and scheduling, you rarely hit single core Turbo.
  • Xenphor - Monday, June 11, 2018 - link

    I suppose but even on the Dolphin forums spreadsheet the highest score is a 249 which is a 7700k at 5.2ghz.
  • Ian Cutress - Tuesday, June 12, 2018 - link

    I'll retest when I'm back home at the end of the week and recovered from jet lag
  • Xenphor - Tuesday, June 12, 2018 - link

    Well don't feel like you have to. Just thought it was weird.
  • Vatharian - Monday, June 11, 2018 - link

    7 years ago, first batches of Core i7-2600K (like mine) were able to reach stable 5.0-5.2 GHz on water, on all 4 cores. Given 7 years difference and 32 vs 14 nm, I am maybe not disappointed (there are +2 cores, half a CPU more), but rather not amused. IPC is higher, that's one, DDR4 can reach 3 times higher frequencies than DDR3, that's two, so there are improvements, but given the bovine excrement that goes on chipset side and PCI-Express connectivity it's clear to see the stagnation.
  • SanX - Monday, June 11, 2018 - link

    Total flop. The processor in your phone is probably more hi-tech, has more transistors, more cores, and was made on more advances factories with 10nm litho being all sold below $25.

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