nbench on small linux devices

One of the benchmark programs that I find most convenient to use is nbench. The reason is that it's applicable on almost every device that can execute plain C code. This means that it can run on a desktop computer as well as on a smartphone (nbench is freely available on Google Play) or a flashed router with a custom firmware (e.g. DD-Wrt with optware).

Here are three devices that I have tried it on:

Raspberry PI

ASUS RT-N16

Linksys NSLU2 

RaspPI and NSLU2 are ARM based where the RT-N16 is MIPS based.

Here you can see the results running it on a Raspberry PI (Raspbian OS):

BYTEmark* Native Mode Benchmark ver. 2 (10/95)
Index-split by Andrew D. Balsa (11/97)
Linux/Unix* port by Uwe F. Mayer (12/96,11/97)

TEST                : Iterations/sec.  : Old Index   : New Index
                    :                  : Pentium 90* : AMD K6/233*
--------------------:------------------:-------------:------------
NUMERIC SORT        :          221.64  :       5.68  :       1.87
STRING SORT         :          31.709  :      14.17  :       2.19
BITFIELD            :      8.4099e+07  :      14.43  :       3.01
FP EMULATION        :          46.363  :      22.25  :       5.13
FOURIER             :          2372.8  :       2.70  :       1.52
ASSIGNMENT          :          2.4781  :       9.43  :       2.45
IDEA                :           696.1  :      10.65  :       3.16
HUFFMAN             :          424.38  :      11.77  :       3.76
NEURAL NET          :          3.0098  :       4.83  :       2.03
LU DECOMPOSITION    :           78.72  :       4.08  :       2.94
==========================ORIGINAL BYTEMARK RESULTS==========================
INTEGER INDEX       : 11.729
FLOATING-POINT INDEX: 3.761
Baseline (MSDOS*)   : Pentium* 90, 256 KB L2-cache, Watcom* compiler 10.0
==============================LINUX DATA BELOW===============================
CPU                 :
L2 Cache            :
OS                  : Linux 3.2.27+
C compiler          : gcc-4.7
libc                : /lib/arm-linux-gnueabihf/libgcc_s.so.1
MEMORY INDEX        : 2.528
INTEGER INDEX       : 3.266
FLOATING-POINT INDEX: 2.086
Baseline (LINUX)    : AMD K6/233*, 512 KB L2-cache, gcc 2.7.2.3, libc-5.4.38
* Trademarks are property of their respective holder.

Here running it on Linksys nslu2 fileserver (flashed with SlugOS):

BYTEmark* Native Mode Benchmark ver. 2 (10/95)
Index-split by Andrew D. Balsa (11/97)
Linux/Unix* port by Uwe F. Mayer (12/96,11/97)

TEST                : Iterations/sec.  : Old Index   : New Index
                    :                  : Pentium 90* : AMD K6/233*
--------------------:------------------:-------------:------------
NUMERIC SORT        :          74.271  :       1.90  :       0.63
STRING SORT         :          6.9679  :       3.11  :       0.48
BITFIELD            :      1.8159e+07  :       3.11  :       0.65
FP EMULATION        :          17.645  :       8.47  :       1.95
FOURIER             :          75.723  :       0.09  :       0.05
ASSIGNMENT          :         0.96228  :       3.66  :       0.95
IDEA                :          176.19  :       2.69  :       0.80
HUFFMAN             :          104.82  :       2.91  :       0.93
NEURAL NET          :         0.10509  :       0.17  :       0.07
LU DECOMPOSITION    :          3.3757  :       0.17  :       0.13
==========================ORIGINAL BYTEMARK RESULTS==========================
INTEGER INDEX       : 3.324
FLOATING-POINT INDEX: 0.136
Baseline (MSDOS*)   : Pentium* 90, 256 KB L2-cache, Watcom* compiler 10.0
==============================LINUX DATA BELOW===============================
CPU                 :
L2 Cache            :
OS                  : Linux 2.6.27.8
C compiler          : gcc version 4.2.4
libc                :
MEMORY INDEX        : 0.668
INTEGER INDEX       : 0.976
FLOATING-POINT INDEX: 0.076
Baseline (LINUX)    : AMD K6/233*, 512 KB L2-cache, gcc 2.7.2.3, libc-5.4.38
* Trademarks are property of their respective holder.

And finally here running it on a Asus RT-N16 router (flashed with DD-Wrt with optware):

BYTEmark* Native Mode Benchmark ver. 2 (10/95)
Index-split by Andrew D. Balsa (11/97)
Linux/Unix* port by Uwe F. Mayer (12/96,11/97)

TEST                : Iterations/sec.  : Old Index   : New Index
                    :                  : Pentium 90* : AMD K6/233*
--------------------:------------------:-------------:------------
NUMERIC SORT        :           160.6  :       4.12  :       1.35
STRING SORT         :          3.7864  :       1.69  :       0.26
BITFIELD            :      6.3597e+07  :      10.91  :       2.28
FP EMULATION        :            28.6  :      13.72  :       3.17
FOURIER             :          19.904  :       0.02  :       0.01
ASSIGNMENT          :           1.753  :       6.67  :       1.73
IDEA                :          670.35  :      10.25  :       3.04
HUFFMAN             :          40.453  :       1.12  :       0.36
NEURAL NET          :        0.015345  :       0.02  :       0.01
LU DECOMPOSITION    :         0.43656  :       0.02  :       0.02
==========================ORIGINAL BYTEMARK RESULTS==========================
INTEGER INDEX       : 5.017
FLOATING-POINT INDEX: 0.023
Baseline (MSDOS*)   : Pentium* 90, 256 KB L2-cache, Watcom* compiler 10.0
==============================LINUX DATA BELOW===============================
CPU                 :
L2 Cache            :
OS                  : Linux 2.6.24.111
C compiler          : gcc version 4.1.1
libc                : ld-uClibc-0.9.28.so
MEMORY INDEX        : 1.011
INTEGER INDEX       : 1.470
FLOATING-POINT INDEX: 0.013
Baseline (LINUX)    : AMD K6/233*, 512 KB L2-cache, gcc 2.7.2.3, libc-5.4.38
* Trademarks are property of their respective holder.

It should be noted that the latter two devices do not feature a floating point unit and thus the performance on floating point intensive is extremely low.

One of the drawbacks of nbench application is that it is written as a single threaded application so it cannot exploit the extra cores of a multicore CPU. One of my future hobby projects could be porting nbench program to OpenMP or even OpenCL in order to exploit the full capabilities of a contemporary CPU or even a GPU. It would be fun of comparing a Raspberry PI with a GTX580 on nbench!