Fullscreen stuttering... Vsync is the whole problem! (proof inside)

[Z3R0B4NG]

hi there,

i see a lot of frustration on the Forum because the game "stutters" in Fullscreen (no matter the resolution or settings)

i have the same effect and it is uber annoying.

i have no solution to this but i made a few observations that might help the DEV's to track this bug down (if anyone knows how to get this info to the Dev's feel free to forward it).



anyway i have a Logitech G15 Keyboard with that nice LCD Display and i am allways running FRAPS to monitor my FPS. (i only tell you so you understand what i'm seeing and you are able to reproduce it).

I noticed if i run Magicka in windowed mode the FPS is CONSTANT 60 FPS (like it is supposed to be if vsync is ON)

-> pic: http://www.imagebanana.com/view/z0b9...ickaFPS001.JPG
you see one straight line


now if i turn Fullscreen ON it looks like this:
http://www.imagebanana.com/view/42wm...ickaFPS003.JPG

obviously it's constantly jumping between 61 and 59 FPS
your eyes of course will notice this as "stuttering".

So the thing that needs fixing is Vsync in Fullscreen.

forcing Vsync OFF:
this works only in Fullscreen for my GTX460 so i am unable to test if it makes any diffrence in windowed mode.

Vsync OFF in Fullscreen is again not constant, with 110 - 115 FPS it stutters even a little worse!
-> http://www.imagebanana.com/view/pgpn...ickaFPS005.JPG

if i return to Windowed mode Vsync is ACTIVE again and i again have the perfectly smooth 60FPS line (same as first pic).


The conclusion of this observation:
The diffrence from Fullscreen to Windowed Mode indicates that Vsync is working completely diffrent in both modes.

Vsync in Fullscreen is the entire Problem but simply turning Vsync off makes it only worse (so dont even bother trying).


this was tested on a Q6600 @ 3,1GHz, GTX 460 (1gig) with 270.61 driver on Win7 x64
... and that is all the info you should need to reproduce this.



hope this helps,
if not... well at least i tried

[wanton74]

I posted this on another thread as well that was posted today.

I have same problem as well and this is bug in XNA framework.
Official XNA code sample that use XNA's own fixed timestep have this exact same problem on my computer.

I made little test code and got same stutters when you have XNA's IsFixedTimeStep setting on.
Then made my own fixed timestep loop and didn't use IsFixedTimeStep setting and test code run smooth.

Developers can fix this easily with making their own fixed timestep game loop for PC version of the game.
Game loop like that is probably max 6 rows of code...very simple to do.

I hope this gets fixed soon...

[Ageyth]

Originally Posted by Z3R0B4NG

obviously it's constantly jumping between 61 and 59 FPS
your eyes of course will notice this as "stuttering".

So the thing that needs fixing is Vsync in Fullscreen.

I can see where you might come to that conclusion, but this is normal in most games. they all jump around a little bit but still appear to be smooth. dropping 1 or 2 frames shouldn't make huge visible stutters at all. so I really doubt this is the reason.

Edit: sorry, didn't read the entire post. I see what you're saying now with Vsync not working properly in fullscreen mode but working fine in windowed. I'd definitely agree. and I think it works in windowed because it uses windows aero to render which already has it's own vsync. so, yeah definitely the way the game vsyncs itself without the desktop or aero is buggy