Ar osu Cluster
Status Report, January 2001
The performan e of the pro essors used in personal omputers (PCs) has steadily in reased.
Present-day PC lo k speeds ex eed the lo k speeds of lassi al super omputers su h as the
Cray. It is widelyre ognized that theoverall omputational speedof a typi al high-endPC is
two or three times inferiorto high-end pro essors su h as the DEC/Compaq Alpha pro essor
be auseofmemorybandwidthlimitationsofPCsupport hips,moreover,pro essorssu hasthe
Alphahavesuperiordouble-pre ision oating-pointar hite ture. Nevertheless,thehigh-volume,
ommodity pri ingof PC omponents (pro essors, mainboards, network interfa e ards, et .)
resultsina ost-e e tive omputer. Inaddition,a lusterofPC omputersprovidesavery ost-
e e tive parallel omputer for programs that use the Single Program Multiple Data (SPMD)
paradigmimplementedwithmessage passing.
A further onsiderationis that the performan eof PCs is proje ted to in reaseby a fa tor of
two in less than two years. One an add PCsto a luster in rementally and the ost of ea h
addition is quite low. In ontrast, the high ost of a ommer ial parallel omputer must be
amortizedovermanyyears.
ThePC lusterat CRS4,namedtheAr osu luster,uses theLinuxoperatingsystem. Forsoft-
ware pa kages that use a Unix-like operating system, support forLinux hasbe ome ommon-
pla e. Afewyearsago,su h ommer ialsoftwarepa kageswere rstportedtoHewlett-Pa kard
HP-UX, IBM AIX, Sili onGraphi sIRIX, et . before theLinuxoperating system was onsid-
ered. In ontrast, re entlytheuseofLinuxhasbe ome widespreadand theUnix-like operating
systems of HP, IBM and SGI have be ome almost ni he markets. In addition, an extensive
range of publi domain software is available for Linux and is in luded in the freely available
distributionsofLinuxsu h asRed Hatand Debian.
TheAr osu lusteratCRS4wasinitiatedneartheendof1999. The rst on guration onsisted
ofthreeHPKayaks(later4Kayaks)anda leserverassembledlo ally. TwootherPCsarealso
loosely asso iated withthe lusterforhistori alreasons.
Re ent News
Towardstheendoftheyear2000, fouradditionalPCswereaddedtothe luster. ThesePCsuse
theServerWorksLE hipsetandfastSCSIdisks. The rstPCsofthe luster(Hewlett-Pa kard
Kayak) use 500 MHz pro essors, 100 MHz memory, 100 MHz Front-Side Bus (FSB), and 60
MHz SCSI harddisks. The mostre ent PCsaddedto the lusteruse 800 MHz pro essors, 133
MHz memoryand FSB,and 160 MHz SCSIharddisks. ThefourKayakPCsand thefourPCs
withthe Server Works hipsetea h have aGigaByte of memory.
In addition, a 24-port Fast Ethernet swit h was added to the luster. A mu h fasterinter on-
ne tion, Myrinet,hasbeenorderedand isexpe ted to arrive nearof theendof January.
Commer ial ompilersforthe parallellanguages OpenMP and High Performan eFortran (and
theFortran90 language)had beenpur hased fromthePortlandGroup(PGI) whenthe luster
began. Re ently,a new versionof PGIsoftware hasbeeninstalled. Inaddition, theoptimizing
C ++
ompilerof Ku kAsso iateshas beeninstalled on the luster,though a problemwith the
li enseserverneeds to beresolved.
In anti ipation of the arrival of Myrinet, it should be mentioned that PGI software an be
on guredtouse Myrinetand Myrinethasimplementeda versionofMessage PassingInterfa e
Installed Software
Do umentation an be found on a luster omputer in subdire tories under /Ar hive/do s.
Underthedire toryhierar hy/Ar hive/do saresymboli linkstodo umentationinsidevarious
software pa kages. In addition, on the omputer ixerri4 an http server has been installed
(Apa he) that has a ess to the hierar hy /Ar hive/do s so users an browse do umentation
withoutloggingintoa luster omputer.
The installedsoftwarein ludes:
PGI PortlandGroupsoftwarefor lusters,whi hin ludesFortran90,HighPerforman eFortran
(HPF)and OpenMP.
FFTW
The "Fastest FourierTransformin theWest" (FFTW), aparallel FFT.
MPI Message Passing Interfa e (MPI) for parallel programs. The distribution MPICH has
beeninstalled.
KAI C++
The optimising ompiler forC ++
developed by Ku k Asso iateshas been installed. This
softwarein ludesKAI'sdebugger.
ORBa us
A high-qualityCORBA implementationforC ++
and Javahas beeninstalled, alledOR-
Ba us,it isbeingdevelopedbyObje tOrientedCon epts,In .
Java
The Java ompiler, virtual ma hine, and related lasses su h as Swing Set, have been
installedon the luster.
DX IBM Data Explore hasbeen installed, a produ t that re entlywas releasedto the publi
domain.
Perl
The a re ent version of Perl has been installed: version 5.6.0. Moreover, a largenumber
of moduleshave beendownloadedfromCPAN.
Geomview
The geometryviewerGeomview hasbeeninstalledon the luster.
Cas ade
Thoughnotdire tlyinstalled onthe luster,thethree-dimensionalgeometrylibraryCas-
ade ompiledforLinuxhasbeeninstalledina subdire toryof theAdvan edLaboratory
proje t(LapS).
