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Howto:Use the system monitor: Difference between revisions
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Howto:Use the system monitor (view source)
Revision as of 13:08, 12 February 2012
, 12 February 2012→OSG on screen stats
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In short: if the framerate '''varies along with the Frame Delay''', then it's a graphics performance issue. If framerate is pretty stable, and Frame Delay '''varies more or less wildly''' I'd suspect some other subsystem being the culprit and causing more or less periodic delays as it needs to do it's stuff. | In short: if the framerate '''varies along with the Frame Delay''', then it's a graphics performance issue. If framerate is pretty stable, and Frame Delay '''varies more or less wildly''' I'd suspect some other subsystem being the culprit and causing more or less periodic delays as it needs to do it's stuff. | ||
= OSG on screen stats = | = Interpreting the OSG on screen stats = | ||
You can also try to play with osg's frame statistics, you can switch that on from the debug menu. | |||
Being CPU and draw limited means the yellow bar is long. And the blue one grows when cull happens | |||
to be a problem. | |||
A simple help is to switch on the onscreen stats in the viewer or flightgear and see if the yellow bar is longer than the orange one. A yellow bar longer than the orange one means that the cpu is not able to saturate the gpu. | |||
Again, beware this does in no way mean that you should write complicated shaders to saturate the gpu! This rather means that the geometry setup/state change time - the yellow one - must decrease! | |||
Once your orange bar is longer than the yellow one, you can start to care for | |||
the shaders and their execution. When thinking about shaders, keep in mind that different GPU's perform very | |||
different on the same shader. | |||
And regarding all that, even if your box already is gpu bound this does not mean that other driver/hardware combinations are gpu bound too. Always: As much as needed and as few as possible. | |||
== References == | |||
* http://www.mail-archive.com/flightgear-devel@lists.sourceforge.net/msg35202.html | |||
* http://www.mail-archive.com/flightgear-devel@lists.sourceforge.net/msg35917.html | |||