Basically just the CPU fan, case, and PSU (if you're lucky). If someone can figure out how to get Doom running on just those 3 things, young people will be able to ascend.
As intended. But a bigger cooler really hits the spot. Try pick up a used one from eBay. Like people here mentioned, other brands have cought up.
The side effect in 2015 was, that I never needed a bigger case for new graphics cards because the fan was already so big.