MPICH.NT was developed by the MPICH people at ANL. It uses a new device that has been created for Windows and supports both SMPs and network connected clusters. To gain maximum performance it has been configured with MPICH_USE_POLLING=1 and MPICH_SINGLETHREAD=1.
We used dual PII, 450 MHz machines to gather the results shown below. All measurements have been made with two processes.
The tested versions of the different implementations are:
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NT-MPICH | : 1.2 |
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MPICH.NT | : 1.2.1 (Feb. 16, 2001) |
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MPI/Pro | : 1.6 |
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WMPI | : 1.53 |
For more details about the benchmark go to the MP-MPICH performance page.
You might also want to take a look at the results of the Pallas MPI Benchmark
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| The charts above show latency (RTT/2) and bandwidth for two dual nodes connected via fast ethernet. Click on one of the pictures to get a table with the results. |
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| The charts above show latency (RTT/2) and bandwidth
for two processes running on one SMP (Dual PII) node. Click on one of the pictures to get a table with the results. |
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vs.
sockets
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| The charts above show latency (RTT/2) and bandwidth
for two processes running on two Dual PII nodes. This time we used the
benchmark of Mark Baker to test the MPI implementations in comparison with a native socket implementation. Click on one of the pictures to get a table with the results. |
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To demonstrate the advantages of real non-blocking communication we created a benchmark that uses MPI_sendrecv instead of doing distinct
MPI_Send/MPI_Recv calls. MPI_Sendrecv is just a shortcut for the sequence MPI_IRecv(); MPI_ISend(); MPI_Waitall();. It is often used if processes have to exchange data. Since ch_wsock2 uses overlapping I/O on sockets, and fast ethernet works in full-duplex mode, messages can really be sent and received simultaneously, especially on a dual processor node. As the charts below show, NT-MPICH achieves a bandwidth of 20 MB/s on fast ethernet and halves the latency in comparison with the standard ping-pong test as shown above.
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| Click on one of the pictures to get a table with the results. | |