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gtmshrm

Member

Registered: 2018-01-26

Posts: 20

Bumblebee malfunction

I have installed bumblebee and nvidia-beta drivers to run my machine leanring code on gpus.
There are 2 issues with it:
1) Technically, I shouldn't be able to use gpu with using the 'optirun' command. But I'm able to access gpu without optirun (but only for python and tensorflow). For everything else I have to use optirun. Is this really a malfunction?
2) My tensorflow code runs slower with 'optirun' command as opposed to without 'optirun'? What can be the reason behind this?

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 25,435

Re: Bumblebee malfunction

1) Depends, elaborate on *accessing*, which commands are you running? optirun/bumblebee doesn't do anything to prevent other software from loading the kernel module on an as needed basis.

2) optirun creates a separate xorg server and synchronizes the xorg server's output back to your intel display, a lot of additional work, for something that isn't necessary in a pure "CUDA/OpenCL/machine learning" context that doesn't rely on graphical output

BTW nvidia-beta has been in sync with the released nvidia for a long time, there are no benefits and only potentially pitfalls from forgetting to recompile on kernel updates by using that.

gtmshrm

Member

Registered: 2018-01-26

Posts: 20

Re: Bumblebee malfunction

Thanks for replying. By *accessing* I meant using programs like nvidia-settings, glxgears, etc. So, If I want to use glxgears on gpu, I would have to use

$ optirun glxgears

whereas if I want to run python code (using tensorflow module) on gpu I can use it even without optirun. I run the code with

$ python test_gpu.py

. What are the advantages/disadvantages of running my code with $ optirun  python test_gpu.py over $ python test_gpu.py? I noticed that optirun uses less gpu memory but is more computationally expensive.

V1del

Forum Moderator

Registered: 2012-10-16

Posts: 25,435

Re: Bumblebee malfunction

That ties in with the 2) answer. If you run clients that need access to a running Xorg server you will need optirun since that will do the necessary groundwork to set up a xorg server over which your client can render its information. Computational workloads obviously don't need that. So in general I'd say running them directly without an intermediate Xorg server is likely to be more useful, but that's something you will have to decide for yourself.