STREAM on AMD Opteron 6220 4-socket system

From: John McCalpin <>
Date: Wed, 27 May 2015 16:26:38 +0000

System is an older Dell 4-socket server using AMD Opteron 6220 processors.
Each processor has 8 cores (4 pairs), running at a nominal 3.0 GHz (3.3 GHz max all-core Turbo).
Each processor has 4 DDR3 DRAM channels.
The system is fairly old -- my first results on this machine are from December 2011 (the Opteron 6220 processor was released in November 2011).
Those original results are broken in a number of ways, so I re-ran the tests with proper array sizes and proper process binding.

If I am interpreting the PCI configuration space data correctly, the system is running the DRAMs at 1333 Mbs, giving a peak memory bandwidth of
4 sockets * 4 channels/socket * 8 Bytes/channel * 1.333 Gtransfers/s = 170GB/s
This is divided up into 8 NUMA nodes, with 2 channels each (21.3 GB/s).

These results were compiled with gcc, so they do not have streaming stores.

John D. McCalpin, Ph.D.
Texas Advanced Computing Center
University of Texas at Austin

Received on Wed May 27 2015 - 17:35:39 CDT

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