Thomas Walter writes: > Dear Otto, > > > Hi Thomas, > > I didnt follow all your discussion. Could it be that your macro is too > > long? At some point (I guess at about 500 lines) the cint buffer which > > keeps the byte code gets full then cint starts interpreting instead of > > running the "compiled" code and this is of course very slow > > > thanks for your sugestion. The investigations showed, that the problem > lies somewhere between root and X11 (see priror mails). In the batch mode > (root -b) I don't have any performance degradations. > It seems that this discussion raises a very important issue, related to the design of ROOT low-level graphics. - ROOT uses raster (as opposite to vector) graphics, it is pixmaps and not X11 "draw primitive" commands which are being passed over the network. Passing pixmaps over the network is not the most time-efficient way of displaying the graphics images. I think that this explains the problems experienced by Thomas. It takes me 10 seconds and even more to redraw a simple canvas when I'm working from home using X-terminal over the modem (28K) connection. In this mode there is a drastic difference in performance between ROOT and PAW graphics with PAW graphics being many (5-10) times faster. Redrawing of more complex event displays takes minutes. - any graphics system which is required to be efficient over the network has to work in client-server mode with the drawing commands and not pixmaps travelling across the ocean. If I remember it correctly a work on the implementation of client-server graphics mode for ROOT has started some time ago but I don't know where the things stand right now. Client-server mode won't help people using X-terminals, but as these are becoming less and less popular, I don't think it is a serious issue. - several big experiments (with Tevatron experiments among them) are planning to take data in the year of 2000, there definitely be a lot of physicists using event display programs in the distributed environment (over the LAN's and WAN's), the issue of performace is a very important one, so it make sense to have a special discussion of client-server graphics mode at the ROOT user workshop planned at Fermilab in the end of March. -pasha
This archive was generated by hypermail 2b29 : Tue Jan 04 2000 - 00:43:29 MET