[Flightgear-devel] Multithreading pattern and frame rate
Hi All I rebuilt from GIT this morning. I am sitting on the runway at a quiet airport, doing absolutely nothing. No AI traffic, no other multiplayers around. Global weather. I have no other applications running, except fgrun. And I am waiting until terrasync has updated all it wants to update and the log window is showing no more activity. I have done two tests, directly after eachother. Same conditions, same METAR. Compared to a version of one week ago, there seems to be a different pattern in CPU usage. The older GIT version had one thread 75% busy and two more threads of about 30% busy and a frame rate of a little over 40 FPS. In the version of today, I have one thread 85% busy and one other thread about 20% busy and the frame rate is about 20 FPS. When I take off and during flight, I have one thread 100% busy all the time, where in the previous versions there were only brief moments that one of the threads was running at 100%. I know there has been done some work on caching and loading of 3D elements... perhaps it is related... Has anyone else noticed a difference? m -- Beautiful is writing same markup. Internet Explorer 9 supports standards for HTML5, CSS3, SVG 1.1, ECMAScript5, and DOM L2 L3. Spend less time writing and rewriting code and more time creating great experiences on the web. Be a part of the beta today http://p.sf.net/sfu/msIE9-sfdev2dev ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] Multithreading pattern and frame rate
Lots of variables. It sounds like you're using up-to-date scenery, so there could have been a change there. New code has also been checked in that deals with paging in the scenery, though I doubt that's causing the problems you are seeing. Can you check out of git the source code from a week ago, compile it, run it, and see if you still see the same performance difference? FPS is not a good performance metric. If you have vsync turned on in your driver, a very tiny change in the time of an operation can make a big fps difference. Also, everyone has different hardware... It's more useful to look at the OSG statistics (choose Cycle On-Screen Statistics twice) and report the times reported for each traversal. Or include a screenshot of them. Did you update anything else, like OSG? Tim On Sat, Nov 20, 2010 at 11:33 AM, fiers...@zonnet.nl wrote: Hi All I rebuilt from GIT this morning. I am sitting on the runway at a quiet airport, doing absolutely nothing. No AI traffic, no other multiplayers around. Global weather. I have no other applications running, except fgrun. And I am waiting until terrasync has updated all it wants to update and the log window is showing no more activity. I have done two tests, directly after eachother. Same conditions, same METAR. Compared to a version of one week ago, there seems to be a different pattern in CPU usage. The older GIT version had one thread 75% busy and two more threads of about 30% busy and a frame rate of a little over 40 FPS. In the version of today, I have one thread 85% busy and one other thread about 20% busy and the frame rate is about 20 FPS. When I take off and during flight, I have one thread 100% busy all the time, where in the previous versions there were only brief moments that one of the threads was running at 100%. I know there has been done some work on caching and loading of 3D elements... perhaps it is related... Has anyone else noticed a difference? m -- Beautiful is writing same markup. Internet Explorer 9 supports standards for HTML5, CSS3, SVG 1.1, ECMAScript5, and DOM L2 L3. Spend less time writing and rewriting code and more time creating great experiences on the web. Be a part of the beta today http://p.sf.net/sfu/msIE9-sfdev2dev ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel -- Beautiful is writing same markup. Internet Explorer 9 supports standards for HTML5, CSS3, SVG 1.1, ECMAScript5, and DOM L2 L3. Spend less time writing and rewriting code and more time creating great experiences on the web. Be a part of the beta today http://p.sf.net/sfu/msIE9-sfdev2dev___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
Re: [Flightgear-devel] Multithreading pattern and frame rate
From: fiers...@zo... - 2010-11-20 10:33 I have done two tests, directly after eachother. Same conditions, same METAR. One thing to note here is that, prior to yesterday's update, the size of the scenery area loaded/rendered at start-up did _not_ depend on the visibility (weather/METAR), neither on any visibility configured manually (command-line etc). FG would always load the same number of tiles at start-up - no matter what the weather/configuration was. This was a bug, since the tile manager didn't bother about visibility changes - and METAR/manually configured visibility was only set _after_ the initial scenery was already scheduled. This has changed yesterday: now, once visibility increases considerably (METAR is received, weather configured) this, as expected, causes an immediate update and loading of all required scenery. So, even if you have configured the same conditions/METAR, this may not be a fair comparison. It's possible that METAR specifies 10nm visibility, but an older FG build would still render only 5nm at start-up (meaning only a quarter of the actually required scenery tiles). With older FG builds, you should wait for METAR to be received, then fly (or reposition) your plane several miles away from the initial location. This location change triggers the scenery scheduler which only then takes the correct visibility into account. I doubt though that this could cause such a severe drop of framerate. And which plane are you using for this comparison? cheers, Thorsten -- Beautiful is writing same markup. Internet Explorer 9 supports standards for HTML5, CSS3, SVG 1.1, ECMAScript5, and DOM L2 L3. Spend less time writing and rewriting code and more time creating great experiences on the web. Be a part of the beta today http://p.sf.net/sfu/msIE9-sfdev2dev ___ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
