From: <cas...@co...> - 2012-06-17 13:00:34
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Hi, This email rekindled an idea from a while back. Last year while working on the 747 sim with multiple projectors and a quad core CPU I experimented with setting up three instances of fgfs - one for each cpu, graphics card, and projector. The improvement in the frame rate was quite dramatic; from around 20-22 fps to over 55 fps for each instance. The down side was that all the dynamic features (3d clouds, AI objects, random stuff, etc) all ran in their own graphics context. so while all the static scenery sync'd across the projectors, the dynamic objects "ended" at the display boundaries. Multi-core machines have been around for some time now. Perhaps it is time to think beyond running Flighgear as a monolithic process in a single CPU configuration. It is my understanding that all three platforms ( MS, Mac, Linux) support some form of shared memory IPCs. I use shared memory in the 737/747 cockpit software to great advantage with a global section for all common data and sharing data between the Captian, FO, and MCDUs processes. In Linux creating a shared memory segment is simple and straight forward. The "master fgfs" would create the shared segment and compute the graphical objects, in this case clouds and AI, and the "fgfs slaves" would simply access the shared segment for the data required to create their visual scene. Hopefully, I'll have some time in the fall to pursue this idea further. In the mean time, the floor is open to anyone who would like to comment or pursue this idea on their own. Regards John W. ----- Original Message ----- From: "Catherine James" <cat...@at...> To: fli...@li... Sent: Friday, June 15, 2012 10:02:34 PM Subject: [Flightgear-devel] Slow frame rates Additional finding: if you do a File --> Reset immediately after startup, the slow 1 - 2 fps problem goes away immediately and frame rates stay high thereafter. Something seems to be getting initialized either when breaking ground during takeoff or in a File --> Reset that is not getting initialized on initial startup. Cathy ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Flightgear-devel mailing list Fli...@li... https://lists.sourceforge.net/lists/listinfo/flightgear-devel |