Vulkan: FPS counter is not working on macOS with Intel integrated GPU

[RevoluPowered]

Godot version

4.0.master

System information

MacOS

Issue description

Using the latest MoltenVK I'm not getting an FPS counter which works in master/4.0

I haven't ever seen it working.

Steps to reproduce

1. Open master on Mac
2. Open viewport info
3. FPS counter will show the wrong values.

Minimal reproduction project

No response

[RevoluPowered]

The data from MacOS.

[RevoluPowered]

Windows 10 results with 3177da1

[bruvzg]

Proper hardware timestamp support was added to the MoltenVK only 12 days ago - KhronosGroup/MoltenVK#1404. Probably, previous software implementation of timestamps (which returns tick count) had insufficient precision to measure frame time.

[bruvzg]

With master (f9696449eae1b99dd7293db6285c21d35e51d539) version on MoltenVK it's showing something, but values seems to be wrong (empty scene is definitely running with more than 6 FPS):

[Calinou]

With master (f9696449eae1b99dd7293db6285c21d35e51d539) version on MoltenVK it's showing something, but values seems to be wrong (empty scene is definitely running with more than 6 FPS):

If the scene is effectively running at very high framerates, then this could mean the GPU time is erroneously being multiplied by 1000 on the MoltenVK side. But I doubt it's running that fast on a hiDPI display, even in an empty scene 🙂

[bruvzg]

then this could mean the GPU time is erroneously being multiplied by 1000 on the MoltenVK side

It's probably not that simple. According to XCode Instruments profiler, average frame time is constant 16.68 ms (60 FPS, v-synced).

[RevoluPowered]

Nice so we can use the xcode instruments to measure frame time :) since its technically using Metal :D

[Calinou]

It's probably not that simple. According to XCode Instruments profiler, average frame time is constant 16.68 ms (60 FPS, v-synced).

V-Sync is enabled by default (and perhaps forced by macOS too), but remember that this new Frame Time panel displays the time taken to render the frame on the GPU, not the time between two frames. This means that even with V-Sync enabled or FPS capped to a low value via low processor mode, it can report framerates above your monitor refresh rate.

It may be unusual at first, but it's definitely a win for laptop users and anyone using V-Sync in general (since you no longer need to make your machine hot and noisy to get accurate FPS reporting).

[bruvzg]

Nice so we can use the xcode instruments to measure frame time :) since its technically using Metal :D

It should be usable for performance monitoring, and MoltenVK is transferring Vulkan pipeline function names and debug comments to the Metal side. It's not a RenderDoc, but should give an overall view.

[KoBeWi]

Is this issue still valid in the newest alpha?

[snougo]

Is this issue still valid in the newest alpha?

Yes, it still valid in beta3, at least on my Intel GPU macbook pro

[snougo]

it still valid in beta5

[lostminds]

I just tried this on my mac (intel 4K iMac with Radeon Pro 560, macOS 13.0.1) and it seems to work fine now for me on 4.0.beta8

[akien-mga]

We've upgraded MoltenVK recently, including several months' work of improvements, so it might have fixed this.

Closing for now, please comment if you can still reproduce this issue in 4.0 beta 8 or later.

[snougo]

it still reproduced in beta9 on IntelGPU Mac

[lostminds]

It still works in beta9 on my mac intel-processor mac with a radeon GPU so it's not a general intel macOS issue (and maybe never was then). So the bug title could be misleading since "Intel macOS" is probably understood as a mac with an intel-based processor (as opposed to the newer M1 processors).