Heiko Schulz wrote > Sent: 31 March 2008 20:45 > To: FlightGear developers discussions > Subject: Re: [Flightgear-devel] CVS - Frame Rates under Windows XP > > >
Vivian Meazza schrieb: > > > Hi > > > > About 10 days ago I got fed up with low frame rates > > using OSG around KSFO, > > so I went out and bought the best nVidia AGP card > > that I could find - 7600gs > > with 512Mb of VRAM. I fitted it with great > > anticipation to my machine - P4 > > 2.8Ghz/800Mhz FSB with 1.5 Gb of RAM running XP - > > and, precisely NOTHING. No > > change in frame rate between the new card and the > > old - a FX6200 with 256Mb > > VRAM - for FG-OSG-HEAD. On the other hand plib-HEAD > > flies. Here are some > > comparative results: > > > > Aircraft: Seahawk > > OSG > > PLIB > > KSFO General Ocean > > KSFO General > > Ocean > > every check box turned to off: > > 25 30 60 > > 45 80 > > 117 > > with everything checked, traffic manager on: > > 15 25 36 > > 25 50 > > 80 > > as above with shadows and 3d clouds: > > > > 18 40 > > 65 > > as above but with trees and precipitation: > > 10 15 40 (but the rain > > turned itself off!) > > > > Aircraft: c172p > > every check box turned to off: > > 33 40 60 > > 45 90 > > 130 > > with everything checked, traffic manager on: > > 27 33 40 > > 30 50 > > 75 > > as above with shadows and 3d clouds: > > > > 30 50 > > 65 > > as above but with trees and precipitation: > > 15 25 30 > > > > Aircraft: Buccaneer (particles) > > as above but with trees and precipitation: > > 8 18 20 > > > > In addition to the difference in frame rate, OSG > > also stutters, while plib > > is commendably smooth. I've tried both executables > > generated here using > > MSVC8, and Fred's pre-cooked binaries. So far as I > > can see the results are > > identical. I've profiled both OSG and plib - for > > anyone interested, some of > > the results are here: > > > > ftp://abbeytheatre2.org.uk/fgfs/OSG/ > > > > While I am no expert in profiling code, the results > > seem to me to show that > > we are getting stuck in the bowels of OSG somewhere, > > while plib is > > well-ordered, with no particular cpu-hog, which is > > pretty much what the > > above table indicates. > > > > My principle concern is that there appears to be > > very little headroom for > > future developments in OSG for shadows, or 3d > > clouds, or landing lights, on > > what is a not-very-old and pretty capable machine. I > > would be grateful if > > some Windows user(s) could confirm at least the > > shape of these comparative > > results. I understand that Linux users get much > > better results than these. > > We might be getting towards the point when Windows > > users are stuck with plib > > (and that's not all bad) while Linux users get to > > play with all the new > > goodies. We might be drifting away from our cross > > platform ethic. > > > > > > Vivian > > > > Luckily the new card wasn't terribly expensive > > otherwise I would be quite > > p'd off > > > Hi, > > With the recent built by Fred I found the old stutters > again- but I could sovle this for me. > > But I can't see any of those problems you have- I can > run FGFS with all features we have - plus heavy > self-written interactive traffic and mp. And the best- > I can run other programs beside too without any > problems (blender as an graphic example!) > > You should know, that you have to set some things on > your pc, Nvidea and FGFS: > > - switch Vsync in the Nvidea settings > - use the frame-rate-throttle! > > I use a CoreDuo 2,6 Ghz and a Gainward 8800GT - but > there were people in the german forum and the official > forum (kid's playground) having no problems with the > recent OSG-built on lower pc. > And the difference between a 8800 and 7600 isn't > really far. > > Even on my old PC with a FX5200 OSG run very pretty at > least. > It is true that OSG is slower than plib- but the > graphic is much better (exxept the 3D-clouds and the > missing shadows)- please not another discussion about > OSG vs Plib! > CoreDuo 2,6 Ghz and a Gainward 8800GT. Not surprised it runs well!!! In particular I think the CoreDuo does threading better than the P4. In case you haven't noticed, the 7600gs is coping easily with the output from FG-OSG - that's why the frame rates didn't increase. And what would Vsync do? The frame rate never gets anywhere near the point at which it might operate. I've tried frame-rate-throttle - it just makes it worse. The graphics are absolutely no different here between OSG or plib that I can see, and why should they be? Could we have some _real_ numbers to compare instead of hearsay. This is not a OSG versus plib discussion - it's a why OSG is so poor on XP discussion Vivian ------------------------------------------------------------------------- Check out the new SourceForge.net Marketplace. It's the best place to buy or sell services for just about anything Open Source. http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace _______________________________________________ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
