REG: QQuickPaintedItem rendering performance halved

  Model Name:	MacBook Pro
  Model Identifier:	MacBookPro13,3
  Processor Name:	Quad-Core Intel Core i7
  Processor Speed:	2.7 GHz
  Number of Processors:	1
  Total Number of Cores:	4
  L2 Cache (per Core):	256 KB
  L3 Cache:	8 MB
  Hyper-Threading Technology:	Enabled
  Memory:	16 GB

Screens: 1, High DPI scaling: inactive
# 0 "Color LCD" Depth: 24 Primary: yes
  Manufacturer: 
  Model: 
  Serial number: 
  Geometry: 1680x1050+0+0 Available: 1680x1025+0+25
  Physical size: 330.791x206.744 mm  Refresh: 60 Hz Power state: 0
  Physical DPI: 129,129 Logical DPI: 72,72 Subpixel_RGB
  DevicePixelRatio: 2 Pixel density: 1
  Primary orientation: 2 Orientation: 2 Native orientation: 0 OrientationUpdateMask: 0

LibGL Vendor: Intel Inc.
Renderer: Intel(R) HD Graphics 530
Version: 2.1 INTEL-16.4.5
Shading language: 1.20
Format: Version: 2.1 Profile: 0 Swap behavior: 2 Buffer size (RGB): 8,8,8
Profile: None (QOpenGLFunctions_-471963040_32766)

Qt Rendering Hardware Interface supported backends:
OpenGL (with default QSurfaceFormat):
  Min Texture Size: 1
  Max Texture Size: 16384
  Max Color Attachments: 8
  Frames in Flight: 1
  Uniform Buffer Alignment: 1
  Supported MSAA sample counts: 1,2,4,8,16
  Features:
    - MultisampleTexture
    v MultisampleRenderBuffer
    - DebugMarkers
    - Timestamps
    - Instancing
    - CustomInstanceStepRate
    - PrimitiveRestart
    v NonDynamicUniformBuffers
    v NonFourAlignedEffectiveIndexBufferOffset
    v NPOTTextureRepeat
    - RedOrAlpha8IsRed
    v ElementIndexUint
    - Compute
    v WideLines
    v VertexShaderPointSize
    - BaseVertex
    - BaseInstance
    v TriangleFanTopology
    v ReadBackNonUniformBuffer
    v ReadBackNonBaseMipLevel
  Texture formats: RGBA8 BGRA8 R8 R16 RED_OR_ALPHA8 BC1 BC2 BC3
Metal:
  Min Texture Size: 1
  Max Texture Size: 16384
  Max Color Attachments: 8
  Frames in Flight: 2
  Uniform Buffer Alignment: 256
  Supported MSAA sample counts: 1,2,4,8
  Features:
    v MultisampleTexture
    v MultisampleRenderBuffer
    v DebugMarkers
    - Timestamps
    v Instancing
    v CustomInstanceStepRate
    v PrimitiveRestart
    v NonDynamicUniformBuffers
    - NonFourAlignedEffectiveIndexBufferOffset
    v NPOTTextureRepeat
    v RedOrAlpha8IsRed
    v ElementIndexUint
    v Compute
    - WideLines
    v VertexShaderPointSize
    v BaseVertex
    v BaseInstance
    - TriangleFanTopology
    v ReadBackNonUniformBuffer
    v ReadBackNonBaseMipLevel
  Texture formats: RGBA8 BGRA8 R8 R16 RED_OR_ALPHA8 RGBA16F RGBA32F R16F R32F D16 D32F BC1 BC2 BC3 BC4 BC5 BC6H BC7