Screen tearing - forcing vsync (move to the Window section?)

[kdunee]

Hi, I'm experiencing severe screen tearing in my application.
I've enabled the vertical synchronization with setVerticalSyncEnabled(true) but to no good effect (both on Windows 7 and Ubuntu 12.04).

However, after manually forcing v-sync in nVidia control panel the tearing miraculously disappeared.

Now here's the thing: I have GeForce GT 620M & Intel HD 3000 working in Optimus setup. On Linux I've disabled the nVidia card altogether to save power and on Windows as far I know Intel is still the default one if there's no existing profile for the application.
Forced v-sync works on both GPUs, setVerticalSyncEnabled(true) works on none.

Is there a stronger way to set v-sync programatically?
EDIT3: browsing around, looking for solution, I've established that we're using wglSwapIntervalEXT(1) to enable v-sync in SFML. Why this wouldn't work remains a puzzle to me

And while I'm on it - does anyone know if the solution from http://developer.download.nvidia.com/devzone/devcenter/gamegraphics/files/OptimusRenderingPolicies.pdf to select stronger GPU in Optimus setups works OK with SFML (I'm going to try it out eventually, but perhaps someone has a quick answer)?
EDIT2: Answering myself and anyone interested: yes, it works I ended up with this code:

#ifdef __MINGW32__
#include <windows.h>
extern "C" {
 __declspec(dllexport) DWORD NvOptimusEnablement = 0x00000001;
}
#endif // __MINGW32__
 

Thanks

EDIT: I think this should actually go to the Window section (http://en.sfml-dev.org/forums/index.php?board=6.0), sorry.

[zsbzsb]

Is there a stronger way to set v-sync programatically?

No there isn't unless you write some very OS/GPU specific code (like you did). I recommend you avoid this route however.

As an alternate solutions you could avoid vsync and instead use RenderWindow.SetFrameRateLimit(...) 

[kdunee]

Ok, thanks for the advice zsbzsb

I'll keep the code to utilise Optimus on Windows anyway, to use stronger GPUs when available.