Message Startup Latencies

Table 1: Time for 1 Byte Messages

	Wsock	WMPI-C	WMPI-J	MPICH-C	MPICH-J	Linux-C	Linux-J
SM	144.8 $\mu$s	67.2 $\mu$s	161.4 $\mu$s	148.7 $\mu$s	374.6 $\mu$s	- $\mu$s	- $\mu$s
DM	244.9 $\mu$s	623.9 $\mu$s	689.7 $\mu$s	679.1 $\mu$s	961.2 $\mu$s	- $\mu$s	- $\mu$s

In Table 1 we show the transmission time in microseconds (s) to send a 1 byte message in each of the environments tested. In SM the mpiJava wrapper adds an extra 94$\mu$s (140%) and 226$\mu$s (152%) compared to WMPI and MPICH C respectively. In DM the mpiJava wrapper adds an extra 66$\mu$s (11%) and 282$\mu$s (42%) compared to WMPI and MPICH C respectively. The Wsock figures are those for a WinSock implementation of PingPong benchmark using TCP. Linux results will be presented during the conference workshop.