Mousing over canvas sluggish when large TTree displayed

I am using win32gdk version 3.10/2 on win2k. I have a TTree that I Draw(“y:x”) If there are, say 5E5 points, mousing over the canvas causes the CPU to peg ast 100% and my status bar (displays x,y) becomes very sluggish. So I do the following:TGraph *pg = (TGraph*)gPad->FindObject("Graph"); if (pg) pg->SetBit(kCannotPick); and that “fixes” the problem. However, when the points displayed is 1.1E6, the mousing over again pegs the cpu. It appears that this occurs once I cross the 1E6 threshold. Any ideas why this happens/what I can do?
Ed Oltman

Mystery “solved”: TTree::Draw(“y:x”) produced a second TGraph object when the number of displayed points exceeds 1E6. Now I do the following: TIter next(gPad->GetListOfPrimitives()); TObject *obj; while( obj = next()) { if (obj->InheritsFrom("TGraph")) obj->SetBit(kCannotPick); } Ed