Using GameObject.transformHandles is slower in Burst compared to a regular context

Package: Burst

Won't Fix

1.8.X

Hey! Thanks for reporting this bug. I looked into this issue and found that this is actually to be expected. The reason is that when you use TransformHandle the getters and setters for position (and the other properties) are external calls that call into the engine. These kinds of calls are not transparent to Burst at all, so they end up being barriers to optimizations, plus there's an overhead to jumping in and out of a Burst call-context (which is what's happening here).

Steps to reproduce:
1. Open the “TransformHandlePerfBug.zip“ project
2. Open Window → General → Test Runner
3. In the Test Runner window, choose “Player“
4. Press “Run All” to run all the tests
5. Compare the difference between “SetPosition_TransformHandle(10000)“ and “SetPosition_TransformHandle_Burst(10000)“ median results

Actual result: “SetPosition_TransformHandle_Burst“ median is larger than the median of “SetPosition_TransformHandle“ (usually between 0.1-0.4 ms)
Expected result: “SetPosition_TransformHandle_Burst“ median is smaller than the median of “SetPosition_TransformHandle“

Reproducible in: 1.8.4 (6000.3.11f1), 1.8.28 (6000.3.11f1, 6000.4.0b11, 6000.5.0a8)
Could not test in: 6000.0.70f1 (Missing TransformHandle class in the Collections package)

Reproduced on: Windows 11 Pro (25H2)
Not reproduced on: No other environment tested

Note: The issue is occasionally not reproducible (if this happens, try to reproduce a few more times)

Using GameObject.transformHandles is slower in Burst compared to a regular context

Package: Burst

Won't Fix

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Have a workaround or additional info about this issue?

Using GameObject.transformHandles is slower in Burst compared to a regular context

Package: Burst

Statuses

Won't Fix

Resolution Notes

Description

Prioritise and Follow this issue

Have a workaround or additional info about this issue?