It depend on the topic as if the topic is such that is familiar to my field and knowledge then can write more. And if unaware by the field or not so familiar then first i take time to know the full detail and information then i need for more time to write the article.
if you want quality content then it will take time like 3 to 4 hours minimum. if anyone write 3 or 4 article in hours i don't think there is quality content