PSTSWM Origin2000 Point-to-Point Communication Performance

Performance Studies using

PSTSWM

SGI Origin2000 SWAP Performance

(ordered swap of 2MB message using SHMEM)

Date/Person:	September 30, 1999 / P. Worley
Platform:	SGI Origin2000 at Los Alamos National Laboratory:
	128 250-MHz MIPS R10000 processors
Environment:	IRIX 6.5
	mpt_1.3.0.0
	MIPSpro Compilers: Version 7.2.1
Communication Library:	SHMEM
SWAP size:	262144 REAL*8 floating point values each direction
Message size:	Largest - 262144 REAL*8 floating point values
	Smallest - 256 REAL*8 floating point values
Processors:	0 and 1
Latency Definition:	(T₁₀₂₄-T₅₁₂)/512
Results:

ordered swap using nonblocking send

Data Statistics
unidirectional bandwidth estimated latency model error

(peak MByte/sec) (usec/msg) (max. rel. error)

1 iter. 187.95 4.52 3.5%

10 iter. 547.36 4.52 22.7%

1 iter. w/overlap 185.49 4.83 7.9%

10 iter. w/overlap 555.24 3.84 23.1%

ordered swap using nonblocking receive

Data Statistics
unidirectional bandwidth estimated latency model error

(peak MByte/sec) (usec/msg) (max. rel. error)

1 iter. 186.43 4.77 1.9%

10 iter. 542.76 4.55 21.0%

1 iter. w/overlap 186.54 4.86 1.7%

10 iter. w/overlap 572.07 2.97 23.3%

ordered swap using nonblocking send and receive

Data Statistics
unidirectional bandwidth estimated latency model error

(peak MByte/sec) (usec/msg) (max. rel. error)

1 iter. 186.51 4.19 9.2%

10 iter. 548.80 4.31 23.6%

1 iter. w/overlap 185.94 4.31 8.2%

10 iter. w/overlap 547.25 4.39 22.2%

ordered swap using ready send

Data Statistics
unidirectional bandwidth estimated latency model error

(peak MByte/sec) (usec/msg) (max. rel. error)

1 iter. 186.26 4.27 1.4%

10 iter. 545.95 4.40 21.7%

1 iter. w/overlap 187.75 4.41 2.1%

10 iter. w/overlap 544.22 4.47 19.3%

DISCUSSION

An Origin2000 processing node consists of one or two processors. If two processors are in a node, they share the node's network interface hardware. In these tests, we examine SHMEM communication performance between processors in the same node.
The experiments using multiple iterations show the effect of the improved memory locality intrinsic to the iteration logic, giving significantly better performance for the smaller message sizes. This is unlikely to be indicative of performance in real applications.

Performance Studies using

PSTSWM

SGI Origin2000 SWAP Performance

(ordered swap of 2MB message using SHMEM)

DISCUSSION

Patrick H. Worley / ( worleyph@ornl.gov) Last Modified Monday, 15-Jul-2002 10:07:37 EDT. 86126 accesses since 1/2/96.

Patrick H. Worley / ( worleyph@ornl.gov)
Last Modified Monday, 15-Jul-2002 10:07:37 EDT.
86126 accesses since 1/2/96.