It wasn’t all that long ago that the majority of consumer CPUs came with regular old thermal paste under their heatspreaders. It’s not just one vendor that did this, either; both AMD and Intel have shipped numerous microprocessors with thermal goop between the silicon die and the nickel plate that serves as an integrated heatspreader (IHS).

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Source: Hot Hardware – Someone Delidded AMD’s Ryzen 7 5800X3D With 3D V-Cache And It Runs Cooler At Higher Clocks