Hello, thanks Bin and Bronis! I fixed it in the latest version. It now reads: "The use of tags for collective operations would prevent certain hardware-optimizations and omitting them is consistent with blocking collective operations." Best, Torsten -- bash$ :(){ :|:&};: --------------------- http://www.unixer.de/ ----- Torsten Hoefler | Postdoctoral Researcher Open Systems Lab | Indiana University 150 S. Woodlawn Ave. | Bloomington, IN, 474045, USA Lindley Hall Room 135 | +01 (812) 855-3608