Martin Spott schreef: > Well, we've been driving two 'external' displays on last years LinuxTag > exhibition using the 'generic' protocol. We were surprised to encounter > a significant performance hit on the master machine serving two clients > at 20 Hz. Throttling the thing down to 10 Hz made the whole setup > flyable again. > Yet this might look different if such master does nothing but FDM > output via network, > > Martin. > Keep in mind that the Generic protocol is one of the most inefficient for real-time data communication, as it communicates via plain text. If you want something that goes over 100Hz, you need to think of a binary system. For an FDM connecting to a visual system it's basically nothing more than 18 floating point values (x,y,z, rotation xyz and first and second order derivatives for smoothing) resulting in a 72-byte data packet, which is doable.
To put it into perspective, the same 18 values would take up at least 200 bytes (characters), not counting newlines and frame separators, as each floating point would need at least 10 characters to be represented at least a bit accurately, and still you have to cope with international issues (comma vs. decimal point) when you're using the generic protocol. Plus a terrible loss in resolution as the max. resolution for a plain text channel can be at most to the 10th decimal place (at least, in standard format) where a double floating point can carry much more accurate data. ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
