STREAM Results on Xeon E3-1270 (Sandy Bridge w/client uncore)

From: John McCalpin <>
Date: Tue, 2 Jun 2015 20:04:05 +0000

Single thread results on Xeon E3-1270 -- single-socket Sandy Bridge with client uncore and 2 channels of DDR3/1333 DRAM.
The Xeon E3-1270 processor has 4 cores with a base frequency of 3.4 GHz and a single-core maximum Turbo frequency of 3.8 GHz.
The system was running with HyperThreading enabled, and the process was bound to logical core 1 using "taskset -c 1".

Other system info (from "lshw"):
product: X9SCL/X9SCM

vendor: Supermicro

4 identical 4 GiB DIMMs

             description: DIMM Synchronous 1333 MHz (0.8 ns)

             product: 9965413-028.A00LF

             vendor: Kingston

             physical id: 0

             serial: 87289B77

             slot: DIMM_1A

             size: 4GiB

             width: 64 bits

             clock: 1333MHz (0.8ns)

These DIMMs appear to be the same as Kingston KVR1333D3E9S/4G, which is a 2-rank, x8 part composed of 18 2Gbit DRAMs.

Two dual-rank DIMMs per channel should give very close to the best possible performance -- it might be a little bit better with a single thread with one dual-rank DIMM per channel (I.e., fewer rank-to-rank stalls), but the difference should be negligible.

Both versions were compiled with the Intel 12.1 C compiler using "-xAVX -ffreestanding -O". The version without streaming stores was done by hacking the assembler to ensure that the code was absolutely positively the same except for the store instructions. Essentially identical results would have been obtained by adding the "-opt-streaming-stores never" flag to the compile line. The default array size was sufficient for this system, since it has only 8 MiB of L3 cache.


Kernel w/streaming stores w/o streaming stores

Copy: 17807.8 12316.9

Scale: 17807.8 12102.6

Add: 18162.1 12976.3

Triad: 18134.3 13136.3

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

Received on Wed Jun 03 2015 - 07:45:49 CDT

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