Much higher system load when fullscreen

I am working on a (until now) simple patch that is loading a spread of filetextures to be able to scratch through them as high performance video playback with variable speed, direction …

When the renderer is in windowed mode the system load in shown in the task manager is close to zero (as expected), but if i switch to fullscreen, system load increases a lot.
Size of the renderer was very similar in windowed and fullscreen mode.

Why does the system load changes that much when switching to fullscreen ?
I can not see a logical reason for this behaviour !?

Intel Core2Quad X9650 3GHz
WinXP Pro32
nvidia GTX285 2GB


fullscreen.jpg (79.9 kB)
not_fullscreen.jpg (81.3 kB)

helo ms,

does it make a difference if you set the renderers presentation interval to “immediate”?

thanks Joreg !

You pointed into the right direction. Setting presentation interval to “immediately” brings system load to 0 in fullscreen mode.

… still strange … isn´t it ?

Does it have to be like this or is this a bug ?


nia. when syncing presentation to vertical refresh directx blocks vvvv until the next refresh comes. see? in windowed mode vsync is not working, therefore the difference…

this is what is causing troubles with videoplayback in fullscreen, but it shouldn’t be a problem for other uses in vvvv since if your application would need more cpu it would still get it and the blocking wait would only be shorter then.

still a good point…i remember there was an option in direct3ds present…that could possibly change that behavior…last time i tried (years ago…) i think it didn’t do anything good though…note to self: check that again.

hm, now i can’t seem to reproduce this…can you provide the patch that does this? and can you show us a screenshot of the perfmeter in both cases and can you try this on a different pc/cpu?

soha, i reduced the patch to the minimum, got rid of all confusing extras and (at least here) the effect is reproducable on different machines.

Attached you find the patch, a folder with sample images and also the two perfmeter screenshots.

Please let me know if you can reproduce it.
(i have to admit, that one time i was not able to reproduce it at first try, but after toggling once between waitforframe an immediately it was there !?)

Markus (2.7 MB)

i am testing this on a:

Intel Core2Duo E8500 3.16GHZ
nvidia 9800GT 512MB

and can’t reproduce it. anybody else? i will keep an eye on this though…


I’ve tried and I also can’t reproduce it.My system loads is around nothing.

I’ve tested with my Asus laptop :

2 GB Ram
WinXP 32
Nvidia GT 8600 GT 512 Mo

In Fullscreen :

In default Presentation interval i’m @ 60 fps and only Present time is around 0.0155

In immediatly Presentation interval i’m @ 102 fps but Windows time loads around and stuck @ 0.0075. This the only load noticable

I would test on others systems in the office