Intel provides estimates of "TDP" which is supposed to correspond to the "base clock" of a chip, even though that frequency is not actually used by the system (???). Intel also sells chips in suites, with different frequencies and core counts, so you could make some guesses about how the process and architecture will behave from them. In the same family, I assume that they still bin their own chips and sell the better ones at higher clocks.
So, for example, the 8700K is specified 500MHz higher than the 8700, and it draws 30W more. So you would guess that the an average 8700 would draw at least 30W extra power if you overclocked it by 500MHz. (Note that this is a 46% increase in heat for a 16% increase in frequency.)
But Intel's specifications do not lead to a consistent picture of power consumption. If you just look at the official specifications of 14nm chips, power per core ranges from 8W to 28W. Trying to estimate overclocking headroom looks impossible because the factory specifications don't suggest a pattern for power consumption. Now that we're getting 8 (or 20...) cores per socket, knowing your real-life thermal flux is necessary if you want your chip to live. The 8700K is specced at 16W per core at "base clocks," but really runs 600MHz higher out of the box on all four cores. If we compare to the 8700 power difference, that suggests that the real life stock heat output reaches 150W, which is obviously a problem if you built a system based on the 95W rating. A lot of good coolers can handle that no problem, but remember that's just the factory setting, which is really 55W higher than claimed. Without even considering overclocking, the same Turbo vs. "base clock" problem means that, if Intel sells an 8-core mainstream chip with an unlocked multiplier in Coffee Lake Refresh, realistic extrapolation suggests you will get out of the box power spikes of 200W. The problem is compounded for i9s: if the 10+ core parts add 5-10W of power in out of the box use you are adding 50-200W of additional heat which is not getting through that polymer very well. This might be part of why Intel no longer claims per-core Turbo settings.
Actually overclocking any of these chips will then lead to unsustainable heat levels in these chips, no matter what fluid is flowing past the lid. It seems very important to accurately test the actual heat given off by the 14++ chips. Is there anyone doing tests of this type to find out how hot they really are?
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