Modern CPU coolers are typical generic aluminum heatsinks with copper 'heat pipe' rods going down the center of them in a few places to distribute heat, and with a blower fan on top. The heat sinks are absolutely massive though.
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That's my machine (well not my exact machine but my model) that big honking black thing in the middle of the case is the blower/ heat sink shroud for the CPU.
It's dead quiet while running, in games in makes a slightly noticeable whir, less than a cdrom spinning up.