Hi Damir,
several remarks:
- don't use TT fonts for high performance.
- don't use scaled fonts for performance.
- use fixed size fonts (e.g. precision 0 or 3 with a pixel size equal to a
natural
pixel size)
- root graphics is always double buffered (this cannot be turned off, and
provides nice smooth updates)
- the bigger the window the more has to be rendered the more time it takes
Most can be gained by optimized font usage.
Cheers, Fons.
- Damir Buskulic wrote:
>
> Hi,
>
> There was a thread a few months ago about drawing speed of ROOT. I'm
> trying to replace PAW routines by ROOT ones in an online data display
> program. The main observed difference is the drawing speed in the case
> of ROOT, which is much slower than PAW. While I can understand this (a
> factor of two in the best case) it is difficult to understand the
> variation of drawing speed with the canvas size. Try the following macro
> :
>
> {
> gBenchmark->Start("toto");
> c1 = new TCanvas("c1","test",10,10,700,700);
> h = new TH1F("h","h",1000,0,10);
> for (int i=1;i<100;i++) {
> h->Fill(gRandom->Gaus(5,1.5),1);
> if (i == 1) h->Draw(); <-- change
gPad->Modified(); <-- add
> gPad->Update();
> }
> gBenchmark->Show("toto");
> }
>
> on my machine this needs around 14 s real time to be completed (Alpha
> XP1000).
> change the size of the canvas to 50x50 (not usable, it's just for
> demonstrating the effect), the real time goes down to 2.8s !
>
> Though fons explained the speed difference between PAW and ROOT, he
> stated that the drawing speed should not depend much on the canvas size.
> This is true for CPU time but not for real time.
>
> I also tested on a distant display, and the results are the same (14s
> and 3s).
>
> In our context, and if this figure cannot be changed, I don't see yet
> how to use root to display in real time a set of 10 histograms or plots.
>
> Anyone has a suggestion ? it will be welcome !
>
> Cheers
>
> Damir
> --
> =====================================================================
> | Damir Buskulic | Universite de Savoie/LAPP |
> | | Chemin de Bellevue, B.P. 110 |
> | Tel : +33 (0)450091600 | F-74941 Annecy-le-Vieux Cedex |
> | e-mail: buskulic@lapp.in2p3.fr | FRANCE |
> =====================================================================
> mailto:buskulic@lapp.in2p3.fr
--
Org: CERN, European Laboratory for Particle Physics.
Mail: 1211 Geneve 23, Switzerland
E-Mail: Fons.Rademakers@cern.ch Phone: +41 22 7679248
WWW: http://root.cern.ch/~rdm/ Fax: +41 22 7677910
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