The factor of 10 is very odd. I'm just using standard root executables
at SLAC. I haven't recompiled it our anything, so I assume they are
optimized to the same level.
I'll send you the file.
----- Original Message -----
From: "Rene Brun" <Rene.Brun@cern.ch>
To: "Arthur E. Snyder" <snyder@SLAC.Stanford.EDU>
Cc: <roottalk@pcroot.cern.ch>
Sent: Tuesday, January 28, 2003 5:57 AM
Subject: Re: CINT cpu speed?
> Art,
>
> I do not understand this factor 10. Are you sure than you run
> with the same CINT optimisation level in both cases?
> Could you send me your file pion-1.612.tuples?
>
> Rene Brun
>
> "Arthur E. Snyder" wrote:
> >
> > I find speed of C++ interpreter to be much slower in new versions of
root
> > than in old ones. Using the code attached below to read in an ASCII file
I
> > find a factor of 2 decrease in the speed of the macro between 3.02-07
> > and 2.23-12. Why is that? This not progress!
> >
> > Even stranger is that the original version of this code which used
"cout"
> > rather than "printf" to print out variable "count" is even slower. That
> > one ran 10x slower in 3.02-07 than 2.23-12 the 1st time it was executed,
> > but improved to only 2x slower when executed again. I'm not sure if this
> > really had anything to do with use of "cout <<" instead of printf,
since
> > other minor changes such as putting in a few statements to print cpu
time
> > used also produced improvement from 10x worse to only 2x worse.
> >
> > Anybody have any idea what's going on here?
> >
> > -Art Snyder, SLAC
> >
> > ASCII tuple reader:
> >
> > TNtuple* readASCII() {
> > ifstream fp("paw/pion-1.612.tuples");
> >
> > TNtuple* temp=new TNtuple("ntuple","ascii
> > data","evtno:npievt:status:idmom:eve:ideve:b:idb:xb:yb:zb:
> > xeve:yeve:zeve:pxpimc:pypimc:pzpimc:ptpimc:ppimc:thpimc:
> > phipimc:pxpirc:pypirc:pzpirc:ptpirc:ppirc:thpirc:phipirc:
> > xpirc:ypirc:zpirc:nsvtpi:ndchpi:lenpi:delth:delthalt:pxalt:
> > pyalt:pzalt:thalt:phialt:xalt:yalt:zalt:pxmom:pymom:pzmom:
> > ptmom:pmom:thmom:phimom:xmom:ymom:zmom:idpimom:idpigma");
> >
> > Float_t array[56];
> > Int_t loop=1;
> > Int_t count=0;
> >
> > while(loop) {
> > for(Int_t i=0; i<56; i++) {
> > fp >> array[i];
> > }
> > temp->Fill(array);
> > count++;
> > if(count>=16434) break;
> > if(count%1000==1) printf("count: %d \n",count);
> > }
> >
> > printf("total: %d \n ",count);
> > return temp;
> > }
> >
> > A.E. Snyder, Group EC \!c*p?/
> > SLAC Mail Stop #95 ((. .))
> > Box 4349 |
> > Stanford, Ca, USA, 94309 '\|/`
> > e-mail:snyder@slac.stanford.edu o
> > phone:650-926-2701 _
> > http://www.slac.stanford.edu/~snyder BaBar
> > FAX:650-926-2657 Collaboration
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