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<blockquote data-quote="Scythe42" data-source="post: 866943" data-attributes="member: 95833">It's a bug in DWM.DWM is only updated in regards to refresh rates when you are on the desktop. This is where you usually change your display properties. That's why the current workaround works on most systems. Also some GPU driver/firmware combinations might prevent this workaround as we are dealing with kernel level functions here in the background not exposed to MP.&nbsp;Digging deep into WDDM might provide a solution to force a DWM update. But I haven't found any functions in the past that seem to do the trick. Probably some private APIs are involved here or we are dealing with kernel level functions, which are out of my area of expertise.Full screen apps are not really supposed to change the refresh rate constantly - except once for backwards compatibility with CRT displays that might require a different refresh rate for different resolutions. As MP relies on DWM to avoid tearing for frame synchronisation to the display, DWM causes a lot of dropped frames in this scenario as assumed fps, set refresh rate, assumes fps by DWM are are not in sync.Initial tests on Win8 showed that this problem has been fixed. At least I cannot reproduce it in the same way anymore. But before getting the hope up wait for the final. Even though Win8 is feature complete it's still worked on and we might face a regression in the final.Also the WDDM 1.2 driver model might play an important role here.</blockquote>

[QUOTE="Scythe42, post: 866943, member: 95833"] It's a bug in DWM. DWM is only updated in regards to refresh rates when you are on the desktop. This is where you usually change your display properties. That's why the current workaround works on most systems. Also some GPU driver/firmware combinations might prevent this workaround as we are dealing with kernel level functions here in the background not exposed to MP. Digging deep into WDDM might provide a solution to force a DWM update. But I haven't found any functions in the past that seem to do the trick. Probably some private APIs are involved here or we are dealing with kernel level functions, which are out of my area of expertise. Full screen apps are not really supposed to change the refresh rate constantly - except once for backwards compatibility with CRT displays that might require a different refresh rate for different resolutions. As MP relies on DWM to avoid tearing for frame synchronisation to the display, DWM causes a lot of dropped frames in this scenario as assumed fps, set refresh rate, assumes fps by DWM are are not in sync. Initial tests on Win8 showed that this problem has been fixed. At least I cannot reproduce it in the same way anymore. But before getting the hope up wait for the final. Even though Win8 is feature complete it's still worked on and we might face a regression in the final. Also the WDDM 1.2 driver model might play an important role here. [/QUOTE]

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