Blender starts on slower GPU, interface and 3D viewport laggy #73296

System Information
Operating system: Windows-10-10.0.17134-SP0 64 Bits
Graphics card: Intel(R) UHD Graphics 630 Intel 4.5.0 - Build 25.20.100.6577

Blender Version
Broken: version: 2.83 (sub 1), branch: master, commit date: 2020-01-18 19:00, hash: c2e62c1292
Worked: 2.81 and previous.

Short description of error
I've noticed laggy and very slow performance in the 3D viewport and in the interface in general in recent 2.82 and 2.83 builds.
Starting the Windows Task Manager shows the culprit: Blender starts on "GPU 0", which is a built-in Intel UHD chip. I've never had this problem before. Checking previous Blender versions, they always automatically choose the faster "GPU 1", which is an Nvidia GeForce RTX 2080 Max-Q.
Rendering with CUDA works normally, Blender switches over to "GPU 1".

Exact steps for others to reproduce the error
Start Blender, look in the task manager which GPU is in use.

Added subscriber: @ZsoltStefan

Added subscriber: @EAW

Changed status from 'Needs Triage' to: 'Needs User Info'

Did you just recently try 2.83, or have you been using 2.82/2.83 for awhile? If so, do you know when this issue started occurring?

What is the model of your laptop? Nvidia GeForce RTX 2080 Max-Q is power saving version.

Have you tried setting Blender to use your NVIDIA card in the NVIDIA control panel?

See https://developer.blender.org/T72447#828971 and the post below it for how to do so.

Also https://docs.blender.org/manual/en/latest/troubleshooting/gpu/windows/nvidia.html#laptops

Triaging note: I am guessing there was a commit that is causing Blender to draw more power is certain laptops, which is setting them to use the slower GPU.

Added subscriber: @Jeroen-Bakker

Blender has no saying in negotiation what GPU it gets. We receive the GPU from the OS. Think that in recent Windows update this mechanism changed as we received several tickets about this.

I haven't used a daily build for a few weeks now. Is there a place where I can find older builds? I could go through them to find the exact time the change happened. The 2.82 build from 2020-01-07 already has the problem.
I did however try some random builds from Graphicall, these work properly. And they are newer than this official one.
VR inspection branch from Jan. 13, 2020
Function Nodes Branch from Jan. 19, 2020

The computer is an Asus ROG Zephyrus S GX531GX, Intel Core i7-8750H, 24GB RAM. I checked the windows power saving settings, they are set to high performance (not power saving), plus I am using it on a power adapter.

The nVidia Control Panel is not available, as this is a work laptop (remote managed).

Added subscriber: @LazyDodo

@ZsoltStefan can you try todays buildbot build ?

Hey, yes it works now!
What was the difference?

Edit: the 2.82 beta build works. The 2.83 alpha still has the problem.

USD added a few thousand exports to the blender binary, which bumped the export of the NvOptimusEnablement symbol from export 119 to export 4754 and i'm unsure why, but when it gets that high the nvidia driver appears to stop seeing/respecting it.

USD on the other hand had no business exporting symbols, which i fixed with D6563 which i landed in 2.82 and merged to master, but somehow the 2.83 build is still using old libraries, have to see what's up there.

Allright, got that sorted out, latest buildbot build has the fix, give it a try!

Yes the latest 2.83 also works, runs on the nVidia GPU.
Thanks for looking into this and for the fix!

Changed status from 'Needs User Info' to: 'Resolved'

Excellent! Glad that it is working. I will close this report and inform the other users who had the same issue.

Download

What's New

Blender Studio

Manual

Developers Blog

Documentation

Benchmark

Blender Conference

Development Fund

One-time Donations

Blender starts on slower GPU, interface and 3D viewport laggy #73296