From Longman Dictionary of Contemporary Englishonly so many/muchonly so many/muchused to say that there is only a limited quantity of something There’s only so much that anybody’s brain can handle at any one time. There are only so many hours in the working day. → so
Examples from the Corpus
only so many/much• It told him it was grass, and grass could hide only so much.• A human being can undergo only so many changes and take in only so many experiences.• I think there was only so much fun to go round, only so much and no more available.• The greens were rougher then, and there was only so much good putting you could do on them.• The truth is there is only so much preparation you can do.• There's only so much you can cling to - your credibility, your belief in small cottage industries - whatever.• There's only so much you can do with hair this fine. 