Adding a few results:

Using OP's code for following

    php 1.8mb/sec
    python 3.8 Mb/sec
    node 1.0 Mb/sec

Java print 1.3 Mb/sec

    echo 'class Code {public static void main(String[] args) {while (true){System.out.print("1");}}}' >Code.java; javac Code.java ; java Code | pv>/dev/null

Java with buffering 57.4 Mb/sec

    echo 'import java.io.*;class Code2 {public static void main(String[] args) throws IOException {BufferedWriter log = new BufferedWriter(new OutputStreamWriter(System.out));while(true){log.write("1");}}}' > Code2.java ; javac Code2.java ; java Code2 | pv >/dev/null