<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <meta name="Generator" content="Microsoft Word 14 (filtered medium)"> <style></style> </head> <body lang="EN-US" link="blue" vlink="purple"> <div class="WordSection1"> <p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">This is somewhat easier to support on windows since windows has the concept of a fullscreen exclusive mode in the OS.<o:p></o:p></span></p> <p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p> <p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">Alex<o:p></o:p></span></p> <p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p> <div style="border:none;border-left:solid blue 1.5pt;padding:0in 0in 0in 4.0pt"> <div> <div style="border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in"> <p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> amd-gfx [mailto:amd-gfx-bounces@lists.freedesktop.org] <b>On Behalf Of </b>Ernst Sjöstrand<br> <b>Sent:</b> Wednesday, August 10, 2016 4:25 AM<br> <b>To:</b> Michel Dänzer<br> <b>Cc:</b> Christian König; Dave Airlie; amd-gfx mailing list; Zhang, Hawking<br> <b>Subject:</b> Re: [PATCH] Add freesync ioctl interface<o:p></o:p></span></p> </div> </div> <p class="MsoNormal"><o:p> </o:p></p> <div> <div> <div> <div> <div> <div> <div> <div> <div> <div> <p class="MsoNormal" style="margin-bottom:12.0pt">I thought I'd add some notes as a someone who also plays games on Windows with Freesync...<o:p></o:p></p> </div> <div> <p class="MsoNormal">I have a 4K monitor with Freesync, the range is 45 to 60 Hz. It might sounds narrow but it allows you<o:p></o:p></p> </div> <div> <p class="MsoNormal">to have a smooth experience even at very high resolutions and settings. If the game can't hit 60 fps<o:p></o:p></p> </div> <div> <p class="MsoNormal">exactly it's still fine, it seems smooth and you don't get tearing.<o:p></o:p></p> </div> <div> <p class="MsoNormal">This is shown in all games as a 60 Hz monitor even though Freesync is enabled.<o:p></o:p></p> </div> <div> <p class="MsoNormal" style="margin-bottom:12.0pt"><br> In the Windows gaming world there's a couple of different combinations at play:<o:p></o:p></p> </div> <p class="MsoNormal">1) Vsync disabled.<o:p></o:p></p> </div> <p class="MsoNormal">The game renders frames simply as fast as it can. If the fps is below 45 I get tearing.<o:p></o:p></p> </div> <p class="MsoNormal" style="margin-bottom:12.0pt">If it's above 60 I get tearing. Not very good solution.<o:p></o:p></p> </div> <p class="MsoNormal">2) Vsync enabled.<o:p></o:p></p> </div> <p class="MsoNormal">Fps stays capped to 60, so no tearing on that end. Also 50 fps is smooth and uses Freesync fine.<br> This is AFAIK done behind the scene by the AMD DX11 implementation and not something the game<o:p></o:p></p> </div> <div> <p class="MsoNormal">is involved in.<o:p></o:p></p> </div> <div> <p class="MsoNormal">If fps goes below 45 it starts locking to 30 fps instead, not so nice.<o:p></o:p></p> </div> </div> <div> <p class="MsoNormal"><o:p> </o:p></p> </div> <p class="MsoNormal">3) Vsync disabled + AMD Frame Rate Target Control (FRTC).<o:p></o:p></p> </div> <p class="MsoNormal">You set FRTC to 1-2 fps below your max refresh rate. That means that if fps goes below 45 you get<o:p></o:p></p> </div> <div> <p class="MsoNormal" style="margin-bottom:12.0pt">tearing (at 45 Hz refresh or 60?), but at least it renders frames as fast as it can in that case still. This is a<br> solution many people like. However FRTC doesn't work all the time.<o:p></o:p></p> </div> <div> <p class="MsoNormal">Regards<o:p></o:p></p> </div> <div> <p class="MsoNormal">//Ernst<o:p></o:p></p> </div> </div> <div> <p class="MsoNormal"><o:p> </o:p></p> <div> <p class="MsoNormal">2016-08-10 9:49 GMT+02:00 Michel Dänzer <<a href="mailto:michel@daenzer.net" target="_blank">michel@daenzer.net</a>>:<o:p></o:p></p> <p class="MsoNormal">On 10/08/16 12:19 PM, Michel Dänzer wrote:<br> > On 09/08/16 07:44 PM, Christian König wrote:<br> >> Am 09.08.2016 um 12:03 schrieb Michel Dänzer:<br> >>> On 09/08/16 06:31 PM, Christian König wrote:<br> >>>><br> >>>> When we add freesync support we just extend vblank_mode with a new enum<br> >>>> to enable it optionally for existing applications.<br> >>> "Just"... this will only be possible after the first 3 steps above.<br> >><br> >> Checking the present extension again we already got PresentOptionAsync<br> >> in there as well.<br> >><br> >> So the whole thing boils down implementing a new vblank_mode enume which<br> >> sets PresentOptionAsync and then doing the right thing on the X side<br> >> with those information.<br> ><br> > PresentOptionAsync isn't for this. It's for not waiting for the vertical<br> > blank period before performing a flip, which may result in tearing. This<br> > distinction still applies with variable refresh rate, so this option<br> > cannot be re-purposed to distinguish between variable and fixed refresh<br> > rate.<br> ><br> ><br> > BTW, the only presentation time we can use for the vblank_mode override<br> > is "now" / "as soon as possible". So for that case (which is currently<br> > the case for basically all games, and will likely continue to be for the<br> > vast majority for a long time), the whole exercise doesn't provide any<br> > net benefit over using the existing vblank-based presentation<br> > infrastructure and just force-enabling variable refresh rate somehow.<br> ><br> > Note that I'm not questioning the value of time-based presentation for<br> > video playback, and thus the need to implement it. I'm only questioning<br> > the point of delaying variable refresh rate for games by gating it on<br> > the time-based presentation infrastructure.<br> <br> Also, we still haven't covered how a variable refresh rate mode would<br> actually get set in this case, assuming it can't be set all the time<br> (because either there is no compositor, or it doesn't use OpenGL, or it<br> doesn't work well with variable refresh rate).<o:p></o:p></p> <div> <div> <p class="MsoNormal"><br> <br> --<br> Earthling Michel Dänzer | <a href="http://www.amd.com" target="_blank">http://www.amd.com</a><br> Libre software enthusiast | Mesa and X developer<br> _______________________________________________<br> amd-gfx mailing list<br> <a href="mailto:amd-gfx@lists.freedesktop.org">amd-gfx@lists.freedesktop.org</a><br> <a href="https://lists.freedesktop.org/mailman/listinfo/amd-gfx" target="_blank">https://lists.freedesktop.org/mailman/listinfo/amd-gfx</a><o:p></o:p></p> </div> </div> </div> <p class="MsoNormal"><o:p> </o:p></p> </div> </div> </div> </body> </html>