> Alex warns: > >JSBSim actually works very hard to simulate realistically and uses > >the processor; with logging turned on, it does significant disk I/O. > >If you're short of memory and having to swap, the extra disk load > >can crucify the performance of Windows to keep the application running. Jon comments: > And we are investigating making logging a positive-action-required feature, > so unwitting users will not run into the disk IO bottleneck.
I've found that each "%f" format conversion is relatively expensive, and (under linux) many sprintf followed by a single write is much faster than a lot of successive fprintf. I'd assume that the C++ version has the same performance impact. So, how about having the logging system giving the user the choice of (a) At crash or exit, the last ten seconds of flight are written to file, or (b) redirect the JSB log stream through the simgear networking interface ? The former eliminates the performance impact at the cost of a fairly small memory array that acts as a queue of doubles. The latter gives the option of making the data accessible from a second computer for real time plotting. I've been using "xoscope" recently, quite successfully, for such things. _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
