I have a large vector (10^9 elements) of chars, and I was wondering what is the fastest way to write such vector to a file. So far I've been using next code: vector<char> vs; // ... Fill vector with data ofstream outfile("nanocube.txt", ios::out | ios::binary); ostream_iterator<char> oi(outfile, '\0'); copy(vs.begin(), vs.end(), oi); For this code it takes approximately two minutes to write all data to file. The actual question is: "Can I make it faster using STL and how"?