[mythtv-users] Fixed!: Nvidia Sync to Vblank pegging cpu in X

Steven Adeff adeffs.mythtv at gmail.com
Wed Dec 20 00:24:11 UTC 2006

On 12/19/06, foo bar <foobum at gmail.com> wrote:
> On 12/17/06, J. Miller <mythtv.org at elvenhome.net> wrote:
> > I've been fighting the scourge of myth causing X to consume 100% of the
> > CPU when Xv Sync to Vblank is turned on in nvidia-settings.  Everything
> > works just fine with it unchecked but that is the only sync setting that
> > gives me a perfect picture with no tearing.  Myth's native OpenGL sync
> > still tears a little.  The problem turned out to be the modeline I was
> > using.  It was a 1368x768 56Hz modeline which apparently triggered the
> > issue.  I switched to a 1360x768 60Hz modeline and now everything works
> > peachy.  X still starts consuming large amounts of CPU occasionally but
> > it quickly drops back down to the 2-4% range.  I'm not 100% sure that it
> > was the refresh but a modeline change did the trick.  Hopefully posting
> > this here will help point others that have the same problem in a new
> > direction.
> NVIDIA have added an option in (I think) 9626 to poll() instead of busy-wait
> for vblank, which fixes the high cpu usage when sync to vblank is switched
> on. It's called "UseEvents".

interesting, you mean in the nvidia-settings Xv section?

I'll have to give this a try.
Before you ask, read the FAQ!
then search the Wiki, and this list,
Mailinglist etiquette -

More information about the mythtv-users mailing list