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Unity Engine

Frame timing manager introduction

Learn about how the Frame Timing Manager works, and which platforms it supports.
Read time 3 minutesLast updated 19 days ago
You can use the 
FrameTimingManager
class to capture high level timing data about individual frame performance in an application. You can then use this data to assess whether your application meets performance targets.
You can use the 
FrameTimingManager
class in the following situations:
Frame timings don't replace data from the Profiler. After you record high level metrics of your application with 
FrameTimingManager
, you can use the Profiler to then investigate specific details.
Note
FrameTimingManager
might decrease GPU performance when it records data on OpenGL ES, so it can't produce an accurate measurement of how your application performs.
To use the data you collect from 
FrameTimingManager
refer to Get frame timing data.

FrameTimingManager data availability

FrameTimingManager
provides results with a set delay of four frames. This is for the following reasons:
  • CPU timing results aren't immediately available at the end of each frame.
  • Unity reads GPU timing results with three frames delay.
Note
The four frame delay doesn't guarantee accurate timing results, because the GPU might not have any available resources to return the results, or might fail to return them correctly.
For a detailed description of available timings, refer to Get frame timing data.
FrameTimingManger
changes how it produces a 
FrameTimeComplete
timestamp under the following circumstances:
  • If the GPU supports GPU timestamps, the GPU provides a 
    FrameTimeComplete
    timestamp.
  • If the GPU doesn't support GPU timestamps but returns a GPU time, 
    FrameTimingManager
    calculates a value for 
    gpuFrameTime
    . The value is the sum of the reported GPU time and the 
    FirstSubmitTimestamp
    values.
  • If the GPU doesn't support GPU timestamps and doesn't return GPU time, 
    FrameTimingManager
    sets the value of 
    PresentTimestamp
    as the value of 
    FrameTimeComplete
    .

Player pause behavior

FrameTimingManager
automatically excludes the amount of time that 
Application.Pause
pauses the applcation from CPU timing measurements. When the application resumes, the 
cpuFrameTime
value for the first resumed frame reflects the actual frame work after resuming, not the time the application spent paused.

Platform support

FrameTimingManager
is supported on the following platforms and graphics APIs:

Platform

Graphics

Supported

AndroidOpenGL ESYes
AndroidVulkanYes
iOSMetalYes
LinuxOpenGLPartial: GPU Frame Time measurement is unsupported.
LinuxVulkanYes
macOSMetalYes
tvOSMetalYes
WebGLWebGLPartial: GPU Frame Time measurement is unsupported.
WindowsDirectX 11Yes
WindowsDirectX 12Yes
WindowsOpenGLYes
WindowsVulkanYes
XROpenGL ESPartial: CPU Render Thread Frame Time and GPU Frame Time measurement is unsupported.
XRVulkanPartial: CPU Render Thread Frame Time and GPU Frame Time measurement is unsupported.

Compatibility with tile-based deferred rendering GPUs

For GPUs that use tile-based deferred rendering architecture, such as Metal GPUs in Apple devices, the reported GPU time might be larger than the reported frame time.
This can happen when the GPU is under heavy load, or when the GPU pipeline is full. In these cases, the GPU might defer execution of some rendering phases. Because 
FrameTimingManager
measures the time between the beginning and end of the frame rendering, any gaps between phases increase the reported GPU time.
In the following example, no GPU resources are available, because the GPU passes a job from the vertex queue to the fragment queue. The GPU's graphics API therefore defers the execution of the next phase. When this happens, the GPU time measurement includes phase work time and any gap in between. The result is that 
FrameTimingManager
reports a higher GPU time measurement than expected.

Diagram showing how the discrepancy in reported GPU time can happen in the Metal API

Additional resources