i5 3470 with DDR3 at 1600 MHz

Table of Contents Introduction Runtimes 1 core 2 cores 4 cores Summary Inferences

Introduction

This page registers the performance achieved with the Intel i5-3470, sporting 4 DDR3 modules of 4GB each at 1600 MHz. The machine used is part of blueCAPE's IT pool.

Notes

The use of mpirun is merely as a helper application. The avxtest* binaries are not running cooperatively.

Keep in mind that these results are not statistically balanced, since they are the result after a single run.

Runtimes

These were executed on CentOS 6.6 x86_64, using a custom build of GCC 4.8.1. Built with the native options:

    g++ -O3 -march=native avxtest.cpp -o avxtest
    g++ -O3 -march=native avxtest64.cpp -o avxtest64

1 core

32-bit:

   ./avxtest

• x86:
  • Time taken (ms): 27050
• AVX:
  • Time taken (ms): 3580

64-bit:

   ./avxtest64

• x86_64:
  • Time taken (ms): 26580
• AVX:
  • Time taken (ms): 7380

2 cores

32-bit:

   mpirun -n 2 ./avxtest

• x86:
  • Time taken (ms): 27250
  • Time taken (ms): 27270
• AVX:
  • Time taken (ms): 3610
  • Time taken (ms): 3610

64-bit:

   mpirun -n 2 ./avxtest64

• x86_64:
  • Time taken (ms): 26790
  • Time taken (ms): 26890
• AVX:
  • Time taken (ms): 7510
  • Time taken (ms): 7440

4 cores

32-bit:

   mpirun -n 4 ./avxtest

• x86:
  • Time taken (ms): 28610
  • Time taken (ms): 28600
  • Time taken (ms): 28600
  • Time taken (ms): 28600
• AVX:
  • Time taken (ms): 3790
  • Time taken (ms): 3790
  • Time taken (ms): 3780
  • Time taken (ms): 3770

64-bit:

   mpirun -n 4 ./avxtest64

• x86_64:
  • Time taken (ms): 28100
  • Time taken (ms): 28080
  • Time taken (ms): 28110
  • Time taken (ms): 28150
• AVX:
  • Time taken (ms): 7810
  • Time taken (ms): 7770
  • Time taken (ms): 7830
  • Time taken (ms): 7900

Summary

Architecture/Mode	1 core	2 cores (std-dev)	4 cores (std-dev)
x86 (ms)	27050	27260 (14.142)	28602.5 (5)
x86_64 (ms)	26580	26840 (70.711)	28110 (29.439)
AVX float (ms)	3580	3610 (0)	3782.5 (9.574)
AVX double (ms)	7380	7475 (49.497)	7827.5 (54.391)
-	-	-	-
Core frequency (MHz) (cpufreq-aperf)	3585	3585	3393
downscale ratio (c1/cx)	1	1	1.0566
x86	1	1.0078	1.0574
x86_64	1	1.0098	1.0576
AVX float	1	1.0084	1.0566
AVX double	1	1.0129	1.0606

Inferences

1. The downscale ratio on the x86/x86_64 calculations are all exactly within the expectable downscale range, given that some slight measurement errors can always occur and the process scheduler can also interfere a bit, since CPU affinity wasn't used.
   • Note: the frequencies were revised with cpufreq-aperf, to compare with the ones at cpu-world.com. Curious details:
     • When using 2 cores, the other 2 cores were prone to working on a close frequency range, usually above 3000 MHz.
     • Using AVX or not resulted in the same frequencies.
2. These results give a clear notion that this CPU uses pure 4 cores, devoid of any HyperThreading features or similar logical cores strategy.
3. For an additional reference, cpubenchmark.net gives an index of 6566 to this CPU.