THE way? It sounds as if GNU Parallel only buffers in one way.

GNU Parallel can handle output in a few ways:

  * --ungroup: With -u output GNU Parallel does not touch the output and output may mix
  * --line-buffer: This buffers a single line from each process.
  * --group: This buffers in files in $TMPDIR. $TMPDIR can point a RAM disk, if you want to buffer in RAM.
  * --sqlworker: This buffers in memory before saving output to an SQL server.

If you are using '&' + 'wait', it pretty much has the same effect as `--ungroup`.