Timing variability when using fullscreen

Development Rendering
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1

I’m currently playing around with PresentMon and for some reason I get a really bad timing when I’m using true fullscreen (r.FullScreeMode 0). I’m rendering with 60FPS and Vsync on. Furthermore, my scene is almost empty. I only present a sphere that changes from white to black after a button press and then back to white. Has anyone an idea, why the timing gets worse with fullscreen and if there is a way to fix that?

This is how the timing looks like in windowed fullscreen:

MsBetweenPresents	MsBetweenDisplayChange	MsInPresentAPI	MsUntilRenderComplete	MsUntilDisplayed
    16324	16706	15480	15865	47931
    16509	16723	15839	16363	48145
    16814	16672	15505	16301	48003
    16555	16699	15863	16338	48147
    16847	16702	15494	16243	48001
    16578	16764	15782	16495	48188
    16723	16739	16188	16945	48204
    17219	16642	15756	16476	47627
    16763	16756	15065	15928	47620
    16066	16611	15718	16465	48164
    16524	16702	15732	16426	48343
    16515	16783	16413	17156	48610
    17382	16588	15305	16061	47817
    16137	16859	16135	16892	48539
    16919	16657	15457	16013	48276
    16313	16623	16269	16982	48586
    17316	16778	15339	16094	48048
    16234	16600	15950	16751	48414
    16956	16801	15523	16325	48258
    16356	16706	16138	16825	48608
    17060	16602	15522	16212	48150
    16316	16716	16130	17015	48549
    17206	16691	15446	16165	48034
    16523	16690	15856	16547	48201
    16866	16863	15441	16071	48198
    16414	16596	15886	16587	48381
    16761	16704	15717	16396	48324
    16591	16650	16081	16788	48382
    17213	16696	15202	15902	47866
    15970	16723	16428	17051	48619
    17601	16756	14996	15666	47773


This is how it looks like when using real fullscreen

MsBetweenPresents	MsBetweenDisplayChange	MsInPresentAPI	MsUntilRenderComplete	MsUntilDisplayed
    13775	16756	15647	36145	46515
    16278	16671	19849	32803	46908
    20999	16726	12742	28570	42634
    13452	16705	15153	35581	45887
    15958	16697	19611	32525	46625
    20822	16614	11745	28298	42418
    12472	16837	15828	35957	46783
    16991	16645	18956	32404	46437
    20143	16683	13217	28882	42978
    14342	16627	14599	34695	45263
    15690	16677	18962	32094	46250
    19763	16783	12363	29066	43270
    13068	16644	15983	36221	46845
    17248	16668	19038	32116	46265
    20252	16816	11867	28603	42830
    12514	16671	17021	36700	46986
    17686	16691	19055	31863	45991
    20232	16741	11673	28222	42500
    12813	16695	15441	35700	46383
    16473	16647	19218	32399	46556
    20116	16746	12336	29033	43187
    13582	16647	16404	35711	46251
    17467	16761	18321	31292	45545
    19690	16657	11642	31783	42511
    12612	16844	19185	32477	46743
    19998	16603	12517	32789	43348
    13401	16606	19393	32488	46552
    20854	16787	12619	28431	42485
    13893	16580	14553	35039	45171
2

Ok, I’ve testet a bit around and it seems that it was caused by setting MaximumFrameLatency to 1. Either by setting it in the console as well as by setting it in the Nvidia settings. When I set it to 2, then everything is fine. Even when I set it to 3 and instead r.FinishCurrentFrame to 1.
Maybe my understanding of r.FinishCurrentFrame is wrong, but I thought that enabling it would be the same as if MaximumFrameLatency is set to 0? Or do I understand r.FinishCurrentFrame wrong?

3

Ok, I think I got the difference between FinishCurrentFrame and MaximumFrameLatency. MaximunFrameLatency is just the number of prerendered Frames by the CPU and FinishCurrentFrame is about fully rendered frames that are buffered by the GPU, right?