Framerate across multiple monitors drops (DX11, multi-viewports) #2970
Description
Dear ImGui 1.75 WIP (17401)
--------------------------------
sizeof(size_t): 4, sizeof(ImDrawIdx): 2, sizeof(ImDrawVert): 20
define: __cplusplus=199711
define: _WIN32
define: _MSC_VER=1914
define: IMGUI_HAS_VIEWPORT
define: IMGUI_HAS_DOCK
--------------------------------
io.BackendPlatformName: imgui_impl_win32
io.BackendRendererName: imgui_impl_dx11
io.ConfigFlags: 0x0000C441
NavEnableKeyboard
DockingEnable
ViewportsEnable
DpiEnableScaleViewports
DpiEnableScaleFonts
io.ConfigViewportsNoDecoration
io.ConfigInputTextCursorBlink
io.ConfigWindowsResizeFromEdges
io.ConfigWindowsMemoryCompactTimer = 60.0f
io.BackendFlags: 0x00001C0E
HasMouseCursors
HasSetMousePos
PlatformHasViewports
HasMouseHoveredViewport
RendererHasVtxOffset
RendererHasViewports
--------------------------------
io.Fonts: 1 fonts, Flags: 0x00000000, TexSize: 512,64
io.DisplaySize: 2141.00,1303.00
io.DisplayFramebufferScale: 1.00,1.00
--------------------------------
style.WindowPadding: 8.00,8.00
style.WindowBorderSize: 1.00
style.FramePadding: 4.00,3.00
style.FrameRounding: 0.00
style.FrameBorderSize: 0.00
style.ItemSpacing: 8.00,4.00
style.ItemInnerSpacing: 4.00,4.00
Version/Branch of Dear ImGui:
Version: 1.75
Branch: docking
Back-end/Renderer/Compiler/OS
Back-ends: imgui_impl_win32.cpp + imgui_impl_dx11.cpp (or specify if using a custom engine/back-end)
Compiler: Visual Studio 2017
Operating System: Windows 10 Pro
My Issue/Question:
greenkalxToday at 1:53 AM
On docking branch, if I move the Demo and Hello viewports to another monitor, the FPS drops to half (of 60fps). Is this due to running on another adapter? Or twice the vsync? (example_win32_directx11)
omarToday at 2:34 AM
@greenkalx could you open an issue, specify which gpu and see if updating drivers makes a difference? Normally that example only wait for vsync on one viewport
Screenshots/Video
Not much to see, just moving the two default viewports to another monitor.
Standalone, minimal, complete and verifiable example: (see #2261)
Just running vanilla imgui from docking branch, no changes.