Performance discrepancy of PingPing vs SendRecv

[sushma-4]

Using IntelOneAPI/2025.2 with IMPI v2021.16 in IMB-MPI1 v2021.10

The official documentation says:

In the case of two processes, Sendrecv is equivalent to the PingPing benchmark of IMB1.x. For two processes, it reports the bidirectional bandwidth of the system, as obtained by the optimized MPI_Sendrecv function

But when I run it on the exactly same two cores, sendrecv outperforms pingping for all sizes:

mpirun -np 2 ./IMB-MPI1 .....

#bytes	Mbytes/sec (PingPong)	Mbytes/sec (PingPing)	Mbytes/sec (SendRecv)
0	0	0	0
1	4.31	3.68	7.43
2	8.9	7.35	14.87
4	16.61	14.47	28.59
8	32.51	29.6	58.55
16	68.8	53.84	118.52
32	141.79	115.19	238.32
64	255.81	181.23	373.96
128	500.49	391.98	807.68
256	927.73	715.7	1512.49
512	1498.66	1203.17	2466.14
1024	2532.21	1998.36	3949.3
2048	4160.18	3214.35	6291.44
4096	5527.35	4414.81	9261.44
8192	6522.92	5468.8	11183.32
16384	7174.1	6546.23	12956.97
32768	7839.75	8239.51	17546.81
65536	10287.31	8336.17	18407
131072	11192.94	13060.11	26332.25
262144	18100.42	13692.36	27133.69
524288	19710.77	13276.27	22186.71
1048576	14577.86	8797.04	13967.69
2097152	13295.74	7716.41	15339.54
4194304	13594.43	7233.45	14542.28

[JuliaRS]

@sushma-4
Did you run on two nodes or two processes on one node?
Did you try another IMPI version?

[sushma-4]

All on single node.
No, only used the latest version