We recently updated our project to 4.13.1 and have been noticing a drop in performance from 4.12.5 so we started digging into it.
I am very confused by the image attached, b/c it would seem that this shot is GPU bound, yet when I profile the GPU it is well below the 11ms mark. My biggest concern is the disconnect between what Stat Unit is telling me the milliseconds are and the GPU profiler’s results. I was fairly positive that previous to this when we would profile that the results from Stat Unit and ProfileGPU were pretty accurate and now I’m not sure what, if anything, changed in 4.13 to cause this.
Am I just reading Stat Unit wrong here? I’m attaching the GPU profile from a another area. Stat Unit was jumping from 12-19ms the entire time here (and dropping occasional frames in the HMD).
This is the GPU Visualizer and the resulting Ouput Log. Are there any glaring red flags here I’m missing? Is this actually a CPU issue?
In my case, a frame needs 10ms to render usually, but sometimes I can see “Other Children” cost another 10ms so the frame rate became 1/2. Wait for a solution.
LogRHI:Warning: Perf marker hierarchy, total GPU time 23.93ms
LogRHI:Warning: Profiled range was continuous.
LogRHI:Warning: 100.0%23.93ms FRAME 533 draws 133445 prims 97973 verts
LogRHI:Warning: 0.2% 0.04ms WorldTick 32 draws 0 prims 0 verts
LogRHI:Warning: 0.0% 0.00ms SlateRenderToTarget 2 draws 0 prims 0 verts
LogRHI:Warning: 0.1% 0.02ms SlateRenderToTarget 2 draws 0 prims 0 verts
LogRHI:Warning: 0.0% 0.00ms SlateRenderToTarget 2 draws 0 prims 0 verts
LogRHI:Warning: 0.0% 0.00ms SlateRenderToTarget 2 draws 0 prims 0 verts
LogRHI:Warning: 0.0% 0.00ms SlateRenderToTarget 2 draws 0 prims 0 verts
LogRHI:Warning: 0.0% 0.00ms SlateRenderToTarget 2 draws 0 prims 0 verts
LogRHI:Warning: 0.0% 0.00ms SlateRenderToTarget 2 draws 0 prims 0 verts
LogRHI:Warning: 0.0% 0.00ms SlateRenderToTarget 2 draws 0 prims 0 verts
LogRHI:Warning: 0.0% 0.00ms SlateRenderToTarget 2 draws 0 prims 0 verts
LogRHI:Warning: 0.0% 0.00ms SlateRenderToTarget 2 draws 0 prims 0 verts
LogRHI:Warning: 0.0% 0.00ms SlateRenderToTarget 2 draws 0 prims 0 verts
LogRHI:Warning: 0.0% 0.00ms SlateRenderToTarget 2 draws 0 prims 0 verts
LogRHI:Warning: 0.0% 0.00ms SlateRenderToTarget 2 draws 0 prims 0 verts
LogRHI:Warning: 0.0% 0.00ms SlateRenderToTarget 2 draws 0 prims 0 verts
LogRHI:Warning: 0.0% 0.00ms SlateRenderToTarget 2 draws 0 prims 0 verts
LogRHI:Warning: 0.0% 0.00ms SlateRenderToTarget 2 draws 0 prims 0 verts
LogRHI:Warning: 50.8%12.16ms Scene 409 draws 132947 prims 96977 verts 4 prims/ms 13 verts/ms
LogRHI:Warning: 0.0% 0.01ms ParticleSimulation 1 draws 208 prims 52 verts
LogRHI:Warning: 0.0% 0.00ms ParticleSimulation 1 draws 208 prims 52 verts
LogRHI:Warning: 0.0% 0.00ms BeginRenderingPrePass 1 draws 0 prims 0 verts
LogRHI:Warning: 0.2% 0.04ms BeginRenderingSceneColor 1 draws 0 prims 0 verts
LogRHI:Warning: 3.0% 0.73ms BasePass 63 draws 19190 prims 14148 verts
LogRHI:Warning: 1.5% 0.36ms View0 30 draws 9316 prims 6788 verts
LogRHI:Warning: 1.3% 0.31ms Static EBasePassDrawListType=0 14 draws 8460 prims 5444 verts 27266 prims/ms 17546 verts/ms
LogRHI:Warning: 0.2% 0.05ms Dynamic 16 draws 856 prims 1344 verts
LogRHI:Warning: 1.6% 0.37ms View1 33 draws 9874 prims 7360 verts
LogRHI:Warning: 1.3% 0.32ms Static EBasePassDrawListType=0 18 draws 9020 prims 6020 verts 28323 prims/ms 18903 verts/ms
LogRHI:Warning: 0.2% 0.05ms Dynamic 15 draws 854 prims 1340 verts
LogRHI:Warning: 0.0% 0.00ms BeginOcclusionTests 0 draws 0 prims 0 verts
LogRHI:Warning: 0.0% 0.00ms BeginOcclusionTests 0 draws 0 prims 0 verts
LogRHI:Warning: 0.2% 0.05ms HZB SetupMip 0 1024x1024 1 draws 1 prims 3 verts
LogRHI:Warning: 0.2% 0.04ms HZB SetupMips Mips:1..9 512x512 9 draws 9 prims 27 verts
LogRHI:Warning: 0.2% 0.05ms HZB 2 draws 1 prims 3 verts
LogRHI:Warning: 0.2% 0.05ms SubmitHZB 2 draws 1 prims 3 verts
LogRHI:Warning: 0.1% 0.01ms TestHZB 1 draws 1 prims 3 verts
LogRHI:Warning: 0.2% 0.04ms HZB SetupMip 0 1024x1024 1 draws 1 prims 3 verts
LogRHI:Warning: 0.2% 0.04ms HZB SetupMips Mips:1..9 512x512 9 draws 9 prims 27 verts
LogRHI:Warning: 0.3% 0.07ms HZB 2 draws 1 prims 3 verts
LogRHI:Warning: 0.3% 0.07ms SubmitHZB 2 draws 1 prims 3 verts
LogRHI:Warning: 0.1% 0.01ms TestHZB 1 draws 1 prims 3 verts
LogRHI:Warning: 0.1% 0.03ms ShadowDepths 6 draws 14228 prims 8036 verts
LogRHI:Warning: 0.1% 0.03ms Atlas0 6144x2048 6 draws 14228 prims 8036 verts
LogRHI:Warning: 0.1% 0.02ms Clear 1 draws 0 prims 0 verts
LogRHI:Warning: 0.0% 0.01ms UEDPIE_0_TestDefaultMainMap.DirectionalLight 5 draws 14228 prims 8036 verts
LogRHI:Warning: 0.0% 0.00ms WholeScene split0 2040x2040 3 draws 6292 prims 3620 verts
LogRHI:Warning: 0.0% 0.00ms WholeScene split1 2040x2040 1 draws 3968 prims 2208 verts
LogRHI:Warning: 0.0% 0.00ms WholeScene split2 2040x2040 1 draws 3968 prims 2208 verts
LogRHI:Warning: 0.1% 0.01ms RenderVelocities 9 draws 1664 prims 2592 verts
LogRHI:Warning: 0.0% 0.00ms View0 0 draws 0 prims 0 verts
LogRHI:Warning: 0.0% 0.00ms LightCompositionTasks_PreLighting 0 draws 0 prims 0 verts
LogRHI:Warning: 0.0% 0.00ms DeferredDecals DRS_BeforeLighting 0 draws 0 prims 0 verts
LogRHI:Warning: 0.0% 0.00ms View1 0 draws 0 prims 0 verts
LogRHI:Warning: 0.0% 0.00ms LightCompositionTasks_PreLighting 0 draws 0 prims 0 verts
LogRHI:Warning: 0.0% 0.00ms DeferredDecals DRS_BeforeLighting 0 draws 0 prims 0 verts
LogRHI:Warning: 0.0% 0.01ms ClearStencilFromBasePass 1 draws 0 prims 0 verts
LogRHI:Warning: 0.0% 0.00ms ClearTranslucentVolumeLighting 1 draws 8 prims 16 verts
LogRHI:Warning: 3.2% 0.76ms Lights 15 draws 62 prims 126 verts
LogRHI:Warning: 3.2% 0.76ms DirectLighting 15 draws 62 prims 126 verts
LogRHI:Warning: 0.0% 0.00ms NonShadowedLights 0 draws 0 prims 0 verts
LogRHI:Warning: 0.0% 0.00ms StandardDeferredLighting 0 draws 0 prims 0 verts
LogRHI:Warning: 0.0% 0.00ms IndirectLighting 0 draws 0 prims 0 verts
LogRHI:Warning: 0.0% 0.00ms UpdateLPVs 0 draws 0 prims 0 verts
LogRHI:Warning: 3.2% 0.76ms ShadowedLights 15 draws 62 prims 126 verts
LogRHI:Warning: 3.2% 0.76ms UEDPIE_0_TestDefaultMainMap.DirectionalLight 15 draws 62 prims 126 verts
LogRHI:Warning: 0.0% 0.01ms ClearLightAttenuation 1 draws 0 prims 0 verts
LogRHI:Warning: 0.9% 0.22ms ShadowProjectionOnOpaque 12 draws 60 prims 120 verts
LogRHI:Warning: 0.5% 0.11ms View0 3 draws 6 prims 12 verts
LogRHI:Warning: 0.1% 0.01ms WholeScene split2 1 draws 2 prims 4 verts
LogRHI:Warning: 0.0% 0.01ms WholeScene split1 1 draws 2 prims 4 verts
LogRHI:Warning: 0.4% 0.09ms WholeScene split0 1 draws 2 prims 4 verts
LogRHI:Warning: 0.5% 0.11ms View1 3 draws 6 prims 12 verts
LogRHI:Warning: 0.0% 0.01ms WholeScene split2 1 draws 2 prims 4 verts
LogRHI:Warning: 0.0% 0.01ms WholeScene split1 1 draws 2 prims 4 verts
LogRHI:Warning: 0.4% 0.09ms WholeScene split0 1 draws 2 prims 4 verts
LogRHI:Warning: 0.0% 0.00ms InjectTranslucentVolume 2 draws 16 prims 32 verts
LogRHI:Warning: 0.0% 0.00ms InjectTranslucentVolume 2 draws 16 prims 32 verts
LogRHI:Warning: 0.0% 0.00ms InjectTranslucentVolume 2 draws 16 prims 32 verts
LogRHI:Warning: 2.2% 0.53ms StandardDeferredLighting 2 draws 2 prims 6 verts
LogRHI:Warning: 0.0% 0.00ms FinishRenderingSceneColor 0 draws 0 prims 0 verts
LogRHI:Warning: 0.4% 0.10ms ScreenSpaceReflections 1512x1680 1 draws 1 prims 3 verts
LogRHI:Warning: 2.0% 0.48ms SSRTemporalAA 2 draws 1 prims 3 verts
LogRHI:Warning: 4.4% 1.06ms ReflectionEnvironment ComputeShader 1512x1680 Tile:16x16 Box:0 Sphere:1 SkyLight:1 1 draws 1 prims 0 verts
LogRHI:Warning: 0.9% 0.21ms ScreenSpaceReflections 1512x1680 3 draws 9 prims 13 verts
LogRHI:Warning: 2.1% 0.51ms SSRTemporalAA 2 draws 1 prims 3 verts
LogRHI:Warning: 3.4% 0.81ms ReflectionEnvironment ComputeShader 1512x1680 Tile:16x16 Box:0 Sphere:1 SkyLight:1 1 draws 1 prims 0 verts
LogRHI:Warning: 0.0% 0.00ms View0 0 draws 0 prims 0 verts
LogRHI:Warning: 0.0% 0.00ms View1 0 draws 0 prims 0 verts
LogRHI:Warning: 0.9% 0.23ms RenderLightShaftOcclusion 1512x1680 (multiple passes) 5 draws 5 prims 15 verts
LogRHI:Warning: 0.9% 0.23ms RenderLightShaftOcclusion 1512x1680 (multiple passes) 5 draws 9 prims 19 verts
LogRHI:Warning: 0.5% 0.11ms ExponentialHeightFog 1512x1680 1 draws 2 prims 4 verts
LogRHI:Warning: 0.4% 0.11ms ExponentialHeightFog 1512x1680 1 draws 2 prims 4 verts
LogRHI:Warning: 18.7% 4.48ms Translucency 183 draws 96892 prims 71026 verts
LogRHI:Warning: 11.1% 2.66ms View0 86 draws 47596 prims 34559 verts 17884 prims/ms 12985 verts/ms
LogRHI:Warning: 0.0% 0.00ms FinishRenderingSceneColor 0 draws 0 prims 0 verts
LogRHI:Warning: 7.6% 1.82ms View1 97 draws 49296 prims 36467 verts 27137 prims/ms 20075 verts/ms
LogRHI:Warning: 0.0% 0.00ms FinishRenderingSceneColor 0 draws 0 prims 0 verts
LogRHI:Warning: 1.3% 0.31ms RenderLightShaftBloom 1512x1680 5 draws 5 prims 15 verts
LogRHI:Warning: 0.0% 0.00ms FinishRenderingSceneColor 0 draws 0 prims 0 verts
LogRHI:Warning: 1.3% 0.30ms RenderLightShaftBloom 1512x1680 5 draws 8 prims 18 verts
LogRHI:Warning: 0.0% 0.00ms FinishRenderingSceneColor 0 draws 0 prims 0 verts
LogRHI:Warning: 5.5% 1.32ms PostProcessing 65 draws 368 prims 610 verts
LogRHI:Warning: 2.8% 0.67ms View0 33 draws 178 prims 300 verts
LogRHI:Warning: 1.1% 0.27ms PostProcessMaterial 1512x1680 Material=PP_Outliner_M 2 draws 1 prims 3 verts
LogRHI:Warning: 0.2% 0.05ms Downsample 756x840 2 draws 9 prims 13 verts
LogRHI:Warning: 0.0% 0.01ms PostProcessEyeAdaptation 1 draws 1 prims 3 verts
LogRHI:Warning: 0.1% 0.02ms PostProcessBloomSetup 756x840 2 draws 1 prims 3 verts
LogRHI:Warning: 0.1% 0.02ms Downsample 378x420 2 draws 9 prims 13 verts
LogRHI:Warning: 0.0% 0.00ms Downsample 189x210 2 draws 9 prims 13 verts
LogRHI:Warning: 0.0% 0.00ms Downsample 95x105 2 draws 9 prims 13 verts
LogRHI:Warning: 0.0% 0.00ms Downsample 47x53 2 draws 9 prims 13 verts
LogRHI:Warning: 0.0% 0.01ms Downsample 24x26 2 draws 9 prims 13 verts
LogRHI:Warning: 0.1% 0.01ms PostProcessWeightedSampleSum#32 12x27 in 24x27 2 draws 9 prims 13 verts
LogRHI:Warning: 0.0% 0.01ms PostProcessWeightedSampleSum#32 24x27 in 48x27 2 draws 9 prims 13 verts
LogRHI:Warning: 0.0% 0.00ms PostProcessWeightedSampleSum#22 24x53 in 48x53 2 draws 9 prims 13 verts
LogRHI:Warning: 0.0% 0.00ms PostProcessWeightedSampleSum#23 48x53 in 96x53 2 draws 9 prims 13 verts
LogRHI:Warning: 0.0% 0.00ms PostProcessWeightedSampleSum#19 48x105 in 95x105 2 draws 9 prims 13 verts
LogRHI:Warning: 0.0% 0.00ms PostProcessWeightedSampleSum#19 95x105 in 190x105 2 draws 9 prims 13 verts
LogRHI:Warning: 0.0% 0.00ms PostProcessCombineLUTs 32x32x32 1 draws 64 prims 128 verts
LogRHI:Warning: 0.5% 0.13ms Tonemapper#4 GammaOnly=0 HandleScreenPercentage=0 1512x1680 2 draws 1 prims 3 verts
LogRHI:Warning: 0.6% 0.14ms PostProcessAA 1 draws 2 prims 4 verts
LogRHI:Warning: 2.7% 0.64ms View1 32 draws 190 prims 310 verts
LogRHI:Warning: 1.1% 0.27ms PostProcessMaterial 1512x1680 Material=PP_Outliner_M 2 draws 1 prims 3 verts
LogRHI:Warning: 0.2% 0.05ms Downsample 756x840 2 draws 10 prims 14 verts
LogRHI:Warning: 0.1% 0.02ms PostProcessBloomSetup 756x840 2 draws 2 prims 4 verts
LogRHI:Warning: 0.1% 0.01ms Downsample 378x420 2 draws 10 prims 14 verts
LogRHI:Warning: 0.0% 0.00ms Downsample 189x210 2 draws 10 prims 14 verts
LogRHI:Warning: 0.0% 0.00ms Downsample 95x105 2 draws 10 prims 14 verts
LogRHI:Warning: 0.0% 0.00ms Downsample 48x53 2 draws 10 prims 14 verts
LogRHI:Warning: 0.0% 0.00ms Downsample 24x26 2 draws 10 prims 14 verts
LogRHI:Warning: 0.0% 0.00ms PostProcessWeightedSampleSum#32 12x27 in 24x27 2 draws 10 prims 14 verts
LogRHI:Warning: 0.0% 0.00ms PostProcessWeightedSampleSum#32 24x27 in 48x27 2 draws 10 prims 14 verts
LogRHI:Warning: 0.0% 0.00ms PostProcessWeightedSampleSum#22 24x53 in 48x53 2 draws 10 prims 14 verts
LogRHI:Warning: 0.0% 0.00ms PostProcessWeightedSampleSum#23 48x53 in 96x53 2 draws 10 prims 14 verts
LogRHI:Warning: 0.0% 0.00ms PostProcessWeightedSampleSum#19 48x105 in 95x105 2 draws 10 prims 14 verts
LogRHI:Warning: 0.0% 0.00ms PostProcessWeightedSampleSum#19 95x105 in 190x105 2 draws 10 prims 14 verts
LogRHI:Warning: 0.0% 0.00ms PostProcessCombineLUTs 32x32x32 1 draws 64 prims 128 verts
LogRHI:Warning: 0.5% 0.13ms Tonemapper#4 GammaOnly=0 HandleScreenPercentage=0 1512x1680 2 draws 1 prims 3 verts
LogRHI:Warning: 0.6% 0.14ms PostProcessAA 1 draws 2 prims 4 verts
LogRHI:Warning: 2.2% 0.52ms SlateUI 70 draws 0 prims 0 verts
LogRHI:Warning: 0.8% 0.19ms SlateUI 22 draws 498 prims 996 verts
LogRHI:Warning: 0.5% 0.12ms CanvasFlush 20 draws 496 prims 992 verts 4220 prims/ms 8440 verts/ms
**LogRHI:Warning: 46.0%11.02ms Other Children**
LogRHI:Warning: Total Nodes 186 Draws 533 approx overhead 2.23ms
LogRHI:Warning: Node histogram 73 buckets
LogRHI:Warning: r.ProfileGPU.Pattern = '*' (using threshold of 5 ms)
LogRHI:Warning: 23.93ms FRAME Events 1 Draws 533
LogRHI:Warning: 12.16ms Scene Events 1 Draws 409
LogRHI:Warning: 4.48ms Translucency Events 1 Draws 183
LogRHI:Warning: 3.80ms View0 Events 6 Draws 152
LogRHI:Warning: 2.94ms View1 Events 6 Draws 165
LogRHI:Warning: 1.86ms ReflectionEnvironment ComputeShader 1512x1680 Tile:16x16 Box:0 Sphere:1 SkyLight:1 Events 2 Draws 2
LogRHI:Warning: 1.32ms PostProcessing Events 1 Draws 65
LogRHI:Warning: 0.99ms SSRTemporalAA Events 2 Draws 4
LogRHI:Warning: 0.77ms UEDPIE_0_TestDefaultMainMap.DirectionalLight Events 2 Draws 20
LogRHI:Warning: 0.76ms DirectLighting Events 1 Draws 15
LogRHI:Warning: 0.76ms Lights Events 1 Draws 15
LogRHI:Warning: 0.76ms ShadowedLights Events 1 Draws 15
LogRHI:Warning: 0.73ms BasePass Events 1 Draws 63
LogRHI:Warning: 0.71ms SlateUI Events 2 Draws 92
LogRHI:Warning: 0.63ms Static EBasePassDrawListType=0 Events 2 Draws 32
LogRHI:Warning: 0.62ms RenderLightShaftBloom 1512x1680 Events 2 Draws 10
LogRHI:Warning: 0.53ms PostProcessMaterial 1512x1680 Material=PP_Outliner_M Events 2 Draws 4
LogRHI:Warning: 0.53ms StandardDeferredLighting Events 2 Draws 2
LogRHI:Warning: 0.45ms RenderLightShaftOcclusion 1512x1680 (multiple passes) Events 2 Draws 10
LogRHI:Warning: 0.31ms ScreenSpaceReflections 1512x1680 Events 2 Draws 4
LogRHI:Warning: 0.28ms PostProcessAA Events 2 Draws 2
LogRHI:Warning: 0.25ms Tonemapper#4 GammaOnly=0 HandleScreenPercentage=0 1512x1680 Events 2 Draws 4
LogRHI:Warning: 0.22ms ShadowProjectionOnOpaque Events 1 Draws 12
LogRHI:Warning: 0.22ms ExponentialHeightFog 1512x1680 Events 2 Draws 2
LogRHI:Warning: 0.18ms WholeScene split0 Events 2 Draws 2
LogRHI:Warning: 0.12ms SubmitHZB Events 2 Draws 4
LogRHI:Warning: 0.12ms HZB Events 2 Draws 4
LogRHI:Warning: Total 60.46ms Events 53 Draws 1825, 46 buckets not shown
LogRendererCore:Warning: FlushRenderingCommands called recursively! 2 calls on the stack.
LogRendererCore:Warning: FlushRenderingCommands called recursively! 2 calls on the stack.
When using the Vive, try to enable/disable reprojection (or better: change it to the “other” value), restart steamvr, restart ue4. Test. Then do the same again (going to the original value for reprojection). This fixed this issue for me at some points (sometimes steamvr has some issues with reprojection and suddenly perma-enables it for some reason, and i managed to “fix” that by the above routine).
Sometimes CPU/GPU boundness is…strange while profiling. So if profilegpu says you are under 11ms, you are probably still cpu-bound. do a stat scenerendering and have a look at your draw-calls.
And dont skip the part 2 just because “it just worked with the prior version”. Maybe you have an issue that results in draw calls being an issue, but you will have to analyze.
I looked at your last frame dump and here are some areas that you need to look into.
100.0%23.93ms FRAME 533 draws 133445 prims 97973 verts
You are drawing 133,445 objects in that single frame, which is too much for VR. You should be drawing maybe 100k at the maximum. Try reducing the amount of objects you are using or introduce some object culling to help reduce this.
Reflection Environments are very expensive and should be disabled in VR.
18.7% 4.48ms Translucency 183 draws 96892 prims 71026 verts
You are also drawing way too much transparency in this scene. Try reducing that and see if it helps. Also you are using to many shadowed lights. For VR you will want to use maily static lighting and use a few stationary and dynamic lights as possible as they are very expensive.