Logo ROOT   6.21/01
Reference Guide
bill.C File Reference

Detailed Description

View in nbviewer Open in SWAN Benchmark comparing row-wise and column-wise storage performance

The test consists in writing/reading to/from keys or trees To execute the benchmark:

root -b -q bill.C or root -b -q bill.C++

for example for N=10000, the following output is produced on an 2.7 GHz Intel Core i7 (year 2011). The names featuring a "t" are relative to trees, the faster, the better.

billw0 : RT= 0.803 s, Cpu= 0.800 s, File size= 45608143 bytes, CX= 1
billr0 : RT= 0.388 s, Cpu= 0.390 s
billtw0 : RT= 0.336 s, Cpu= 0.310 s, File size= 45266881 bytes, CX= 1.00034
billtr0 : RT= 0.229 s, Cpu= 0.230 s
billw1 : RT= 1.671 s, Cpu= 1.670 s, File size= 16760526 bytes, CX= 2.72078
billr1 : RT= 0.667 s, Cpu= 0.680 s
billtw1 : RT= 0.775 s, Cpu= 0.770 s, File size= 9540884 bytes, CX= 4.74501
billtr1 : RT= 0.352 s, Cpu= 0.350 s
billtot : RT= 5.384 s, Cpu= 5.290 s
******************************************************************
* ROOTMARKS =1763.9 * Root6.05/03 20150914/948
******************************************************************
#include "TFile.h"
#include "TSystem.h"
#include "TH1.h"
#include "TRandom.h"
#include "TStopwatch.h"
#include "TKey.h"
#include "TTree.h"
#include "TROOT.h"
const Int_t N = 10000; //number of events to be processed
TStopwatch timer;
void billw(const char *billname, Int_t compress) {
//write N histograms as keys
timer.Start();
TFile f(billname,"recreate","bill benchmark with keys",compress);
TH1F h("h","h",1000,-3,3);
h.FillRandom("gaus",50000);
for (Int_t i=0;i<N;i++) {
char name[20];
sprintf(name,"h%d",i);
h.SetName(name);
h.Fill(2*gRandom->Rndm());
h.Write();
}
timer.Stop();
printf("billw%d : RT=%7.3f s, Cpu=%7.3f s, File size= %9d bytes, CX= %g\n",compress,timer.RealTime(),timer.CpuTime(),
(Int_t)f.GetBytesWritten(),f.GetCompressionFactor());
}
void billr(const char *billname, Int_t compress) {
//read N histograms from keys
timer.Start();
TFile f(billname);
TIter next(f.GetListOfKeys());
TH1F *h;
TKey *key;
Int_t i=0;
TH1F *hmean = new TH1F("hmean","hist mean from keys",100,0,1);
while ((key=(TKey*)next())) {
h = (TH1F*)key->ReadObj();
hmean->Fill(h->GetMean());
delete h;
i++;
}
timer.Stop();
printf("billr%d : RT=%7.3f s, Cpu=%7.3f s\n",compress,timer.RealTime(),timer.CpuTime());
}
void billtw(const char *billtname, Int_t compress) {
//write N histograms to a Tree
timer.Start();
TFile f(billtname,"recreate","bill benchmark with trees",compress);
TH1F *h = new TH1F("h","h",1000,-3,3);
h->FillRandom("gaus",50000);
TTree *T = new TTree("T","test bill");
T->Branch("event","TH1F",&h,64000,0);
for (Int_t i=0;i<N;i++) {
char name[20];
sprintf(name,"h%d",i);
h->SetName(name);
h->Fill(2*gRandom->Rndm());
T->Fill();
}
T->Write();
delete T;
timer.Stop();
printf("billtw%d : RT=%7.3f s, Cpu=%7.3f s, File size= %9d bytes, CX= %g\n",compress,timer.RealTime(),timer.CpuTime(),
(Int_t)f.GetBytesWritten(),f.GetCompressionFactor());
}
void billtr(const char *billtname, Int_t compress) {
//read N histograms from a tree
timer.Start();
TFile f(billtname);
TH1F *h = 0;
TTree *T = (TTree*)f.Get("T");
T->SetBranchAddress("event",&h);
TH1F *hmeant = new TH1F("hmeant","hist mean from tree",100,0,1);
Long64_t nentries = T->GetEntries();
for (Long64_t i=0;i<nentries;i++) {
T->GetEntry(i);
hmeant->Fill(h->GetMean());
}
timer.Stop();
printf("billtr%d : RT=%7.3f s, Cpu=%7.3f s\n",compress,timer.RealTime(),timer.CpuTime());
}
void bill() {
TString bill = dir + "/bill.root";
TString billt = dir + "/billt.root";
TStopwatch totaltimer;
totaltimer.Start();
for (Int_t compress=0;compress<2;compress++) {
billw(bill,compress);
billr(bill,compress);
billtw(billt,compress);
billtr(billt,compress);
}
gSystem->Unlink(bill);
gSystem->Unlink(billt);
totaltimer.Stop();
Double_t realtime = totaltimer.RealTime();
Double_t cputime = totaltimer.CpuTime();
printf("billtot : RT=%7.3f s, Cpu=%7.3f s\n",realtime,cputime);
//reference is a P IV 2.4 GHz
Float_t rootmarks = 600*(16.98 + 14.40)/(realtime + cputime);
printf("******************************************************************\n");
printf("* ROOTMARKS =%6.1f * Root%-8s %d/%d\n",rootmarks,gROOT->GetVersion(),gROOT->GetVersionDate(),gROOT->GetVersionTime());
printf("******************************************************************\n");
}
Author
Rene Brun

Definition in file bill.C.