At office, using the internal LAN at my disposal, I'm having a go at parallel
computing - to begin with - with pvm, rpvm & snow.
The two boxes are as follows
Remote machine uffbsd:
CPU: Intel(R) Pentium(R) 4 CPU 2.00GHz (1994.13-MHz 686-class CPU)
Origin = "GenuineIntel" Id = 0xf24 Stepping = 4
real memory = 260046848 (248 MB)
This machine NbBSD:
CPU: Mobile Intel(R) Pentium(R) 4 - M CPU 2.00GHz (1993.54-MHz 686-class CPU)
real memory = 536674304 (511 MB)
And starting library snow under R I have the following situation
clusterCall(cl, function() Sys.info()[c("sysname",
"release","nodename","machine")])
[[1]]
sysname release nodename machine
"FreeBSD" "5.4-RELEASE" "uffbsd.myd" "i386"
[[2]]
sysname release nodename machine
"FreeBSD" "6.0-RELEASE" "NbBSD.myd" "i386"
NOW,
using the example of boot in the end of page
http://www.stat.uiowa.edu/~luke/R/cluster/cluster.html
I find this amazing result:
system.time(cl.nuke.boot<-
clusterCall(cl,boot,nuke.data,nuke.fun,R=999,m=1,fit.pred=new.fit,x.pred=new.data))
[1] 0.0078125 0.0078125 27.9609375 0.0000000 0.0000000
boot(nuke.data,nuke.fun,R=999,m=1,fit.pred=new.fit,x.pred=new.data))
[1] 26.976562 0.109375 28.484375 0.000000 0.000000
There's not that much gain in time between my cluster and the local
computation, isn't it.
Now my question is:
What could have been gone wrong and what should I verify?
Ciao
Vittorio