Dual Monitor slowdown
BlitzMax Forums/BlitzMax Programming/Dual Monitor slowdown
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OK, so i've got an app which takes X time to process. I'm using Flip 0, as I don't care about waiting for vblank. I'm running on two monitors (with a NVidia Quadro FX1400): Monitor A: 1600 *1200 Monitor B: 1920 * 1200 With the app (it's a windows prog) runs on Monitor A, it runs nice and fast. BUT, dragging the window onto Monitor B, and it slows down a LOT. I'm using the MilliSecs command to compare the time between screen refreshes. On Monitor A, this is around 0-1, but on Monitor B it's up at 20-30. To test this, I've just got one function in a main tight loop: Graphics 1400,900,0 Function UTILITY_Flip() d=MilliSecs()-LastSync SetColor 0,255,0 jDrawText (SyncCount/60)+" Sync: "+d,800,10 SetColor 255,255,255 LastSync=MilliSecs() SyncCount:+1 Flip 0 id=PollEvent() If id=259 Print "quit" End EndIf End Function Function jDrawText (n$,x,y) h=TextHeight(n$) w=200 GetColor r,g,b SetColor 0,0,0 DrawRect x,y,w,h SetColor r,g,b DrawText n$,x,y End Function If I set the graphics to Graphics 1400,90,0 ..it's better, but the SyncCount still goes up much slower on Monitor B. Other people have also tested this with their dual monitors and get the same kind of issue. Anyone have any ideas? (and yes, i've tried turing hardware acceleration to full / off, but it makes no difference) |
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It makes no difference to what you set the hardware acceleration. The moment you push it to screen 2 it will be dual screen hardware acceleration which means degrade of performance as the screen area gets larger. Just don't do it and you do not have a problem. Do it and be aware that dualscreen hardware acceleration has its price. That simple it is. |
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Changing to GL drivers seems to help a lot.. |
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Thats clear, DX7 never was supposed to be used on such systems, back then there was no graphic hardware capable of it, most cards were not even capable of doing 1024x768 fullscreen hardware acceleration on 32bit depth. |
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IIRC the 2nd monitor will use software 3D acceleration, not hardware. DX/driver issue, not Blitzmax... |
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A heads up for those that still care, Windows Embedded Standard 2001 does not suffer from this problem (maybe true for Windows 7)! A bold statement I know but as a crude example I wrote an application that when ran under XPe and dragged to the second monitor the frame rate fell from 100FPS to 8FPS the same on 2011 Quebec was 70FPS on both screens. |