what is hardcore gaming?

Depends on what you mean by hardcore. Somebody who spends 12 hours every day playing games is hardcore. It wouldn't take much toll on the GPU but you may suffer from an angry girlfriend, turning a whiter shade of pale and an acute lack of social skills in the long run. Other side effects could include an excess hankering after hot pockets and energy drinks

In som extreme cases people have been known to pee in bottles and avoiding showers except on patch day