1. Overview

The High Energy Physics (HEP) SPEC benchmark is a set of test applications which stress the processor with operations and algorithms used commonly in applications from the physics community, and provide the SPEC result used for example in describing the resources relevant to HEP applications, provided to the Grid infrastructure. Alternatively the HEPSPEC benchmark suite can be used to assess the condition of different configurations and detect latent bottlenecks and problems.

2. Interactive script for HEPSPEC runs

You can find the interactive script for running HEPSPEC benchmarks on both local machines and in SGE farm in AFS under

/afs/ifh.de/group/rz/HEPSPEC/interactiveHEPSPEC.sh . This script takes several parameters, the description of which can be obtained by running the script with the '-h' option:

host /afs/ifh.de/group/rz/HEPSPEC
10-05-12 13:55 # ./interactiveHEPSPEC.sh -h

Please specifiy the required arguments!
# ./genericSPEcrun.sh [compiler] [architecture] [run mode]
Valid values are:
        for [compiler]     : icc or gcc
        for [architecture] : 32 or 64
        for [mode]         : farm or local

HEPSPEC benchmarks can be run with Intel icc v. 11.0 or GNU GCC v. 4.1.2 . Furthermore one can choose between compiling and running the HEPSPEC benchmarks for 32 or 64 bit architecture and whether to run in a local environment or on some of the SGE farm hosts. The tests reported in Section 4 were run with gcc for 32 bit architecture as perscripted by HEP computing community.

2.1. Running HEPSPEC in the SGE Farm

Here is an example of submitting a HEPSPEC benchmark run to a host in the SGE Farm using icc as compiler and 32 bit architecture:

host /afs/ifh.de/group/rz/HEPSPEC
10-05-12 14:06 # ./interactiveHEPSPEC.sh icc 32 farm
Full path to the unmodified HEPSPEC distribution:
/afs/ifh.de/group/rz/HEPSPEC/2006-1.1
Setting SPECDIR= /afs/ifh.de/group/rz/HEPSPEC/2006-1.1

Full path to the CERN HEPSPEC .cfg file:
/afs/ifh.de/group/rz/HEPSPEC/spec2k6
Setting CERNCONFDIR= /afs/ifh.de/group/rz/HEPSPEC/spec2k6

Full path to folder for storing the result (must not be in the temporary folder)
/afs/ifh.de/group/rz/HEPSPEC/SPECresultsDESY
Setting RESULTDIR= /afs/ifh.de/group/rz/HEPSPEC/SPECresultsDESY

Submitting /afs/ifh.de/group/rz/HEPSPEC/framHEPSPEC.sh
Your job 792245 ("farmHEPSPEC.sh") has been submitted

The "interactiveHEPSPEC" scripts submits a so-called subscript, farmHEPSPEC, which has the following options embedded, according to the rules for running farm jobs found in Batch System Usage.

#(the cpu time for this job)
#$ -l h_cpu=09:00:00
#(the maximum memory usage of this job)
#$ -l h_vmem=768M
#(Acquire disk space)
#$ -l tmpdir_size=4G
#(stderr and stdout are merged together to stdout)
#$ -j y
#(send mail on job's end and abort)
#$ -m bae
#(Execute the sript from the current working directory)
#$ -cwd
#(specifiy project)
#$ -P yourgrouphere
#(parallelism level)
#$ -pe multicore 8
#(reserve slot for the whole job)
#$ -R y

2.2. Running HEPSPEC locally on a given machine

If you want to test a particular machine to which you have login access you can do this by invoking the script with the 'local' parameter. In this case you will be additionally asked for the path where to create and use a temporary folder for copying and compiling the HEPSPEC benchmarks. Note that this path should point to a folder which can hold at least 4 GB data, otherwise the HEPSPEC benchmark will exit with an error.

10-05-12 14:30 # ./interactiveHEPSPEC.sh gcc 32 local
Full path to the unmodified HEPSPEC distribution:
/afs/ifh.de/group/rz/HEPSPEC/2006-1.1
Setting SPECDIR= /afs/ifh.de/group/rz/HEPSPEC/2006-1.1

Full path to the CERN HEPSPEC .cfg file:
/afs/ifh.de/group/rz/HEPSPEC/SPEC/spec2k6
Setting CERNCONFDIR= /afs/ifh.de/group/rz/HEPSPEC/SPEC/spec2k6

Full path to temporary scratch folder for HEPSPEC copy and compile (about 4BG):
(DON'T ENTER YOUR AFS HOME DIRECTORY)
/tmp
Setting TEMPDIR= /tmp

Full path to folder for storing the result (must not be in the temporary folder)
/afs/ifh.de/group/rz/HEPSPEC/SPECresultsDESY
Setting RESULTDIR= /afs/ifh.de/group/rz/HEPSPEC/SPECresultsDESY

***************************************************
Starting on host host.ifh.de at 20100512, argc=3
***************************************************
SPECDIR     = /afs/ifh.de/group/rz/HEPSPEC/2006-1.1
CERNCONFDIR = /afs/ifh.de/group/rz/HEPSPEC/SPEC/spec2k6
COMPILER    = gcc
ARCH        = 32
TEMPDIR     = /tmp
Hit any key to continue....
Using GNU C/C++ compiler suite
Logfile name is HEPSPEC_host.ifh.de_gcc_20100512_cerncfg.log
Copy the installation files to TEMPDIR

3. Results

The following table holds the results for running the HEP SPEC becnhmarks with the default configuration file provided by CERN and run with the 'gcc', '32' and 'farm' parameters.

This table summarizes the minimum, maximum and average results for the different processor types:

The following table holds the results for running the HEP SPEC becnhmarks with the default configuration file provided by CERN and run with the 'gcc', '64' and 'farm' parameters.

As one can see from the tables above, the slight performance gain whe running the benchmark in the 64-bit mode is about 10,4% on the PAX machines (Xeon X5560), about 16% on the SMT-enabled photon host as well as on the machines in the blade9 chasis. Interesting fact to mention is that the machines blade0x through blade6x show similar results in both 32 nad 64-bit mode. This could be due to the fact that the processors Xeon E5345, Intel Xeon 5160, Intel Xeon 5440 and Intel Xeon E5450 rely on the old CPU interconnect to the main memory, namely the FSB which operates on a static frequency and so the time for 32 bit accesses translates into the time for a 64 bit accesses to main memory.