Same speed with GPU than with CPU?

Blender's renderer and external renderer export

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Fran
Posts: 4
Joined: Tue Jan 01, 2013 12:47 pm

Same speed with GPU than with CPU?

Postby Fran » Tue Jan 01, 2013 12:51 pm

Hi there,

I have an Ubuntu box where I have been able to install and enable CUDA for my nVidia GeForce GT610, so I can select its GPU on Blender for rendering instead the CPU.

The problem is that the render takes the same time with the GPU than with the CPU. I was no expecting this graphic card to be awesome, but the problem is that the rendering time is EXACTLY the same for the same scene, so I think it may not be using the GPU at all even when it lets me select it.

Any ideas for debugging this problem? How could I make sure of what device is blender using for rendering?

Thanks a lot in advance,

Fran
Posts: 4
Joined: Tue Jan 01, 2013 12:47 pm

Postby Fran » Tue Jan 01, 2013 1:17 pm

I have even changed the GPU behaviour from "adaptative" to "perfomance" with nvidia-settings application and there were no changes at all, so it actually seems like Blender is NOT using the GPU, whatever settings I put.

Pi x Om
Posts: 9
Joined: Tue Dec 25, 2012 2:33 am
Location: space

Postby Pi x Om » Tue Jan 01, 2013 5:33 pm

happy new year ;)

do you monitoring cpu/gpu usage?
u should, bcs u could be sure about whats used or not :)

for cuda usage u need to enable it in the user prefs
and then in the render tab/device: cpu to gpu.

at another thing, i am not sure if it can work in a (virtual) box.

br

Fran
Posts: 4
Joined: Tue Jan 01, 2013 12:47 pm

Postby Fran » Tue Jan 01, 2013 6:51 pm

Happy new year to you too.

Of course I have selected my GeForce GPU on User preferences instead of the CPU, that's exactly the point...

I do not know how to monitory gpu usage, although top command shows that CPU usage by blender boosts when making a render, even when GPU has been selected as render device, so it seems like it were using the CPU anyway, no matter what I set on user preferences.

I am not using a virtual box, but actual hardware.

Bests,

Pi x Om
Posts: 9
Joined: Tue Dec 25, 2012 2:33 am
Location: space

Postby Pi x Om » Tue Jan 01, 2013 11:29 pm

u didn´t said what system u have (cpu importand)
but on my system when I render with cpu it uses 4 cores, when i render with gpu,
it uses one cpu core.
here on windows we have task manager, where u can see cpu usage or another way desktop widgets.
I am not sure if there is something like these available on linux :D

Tehrasha
Posts: 1264
Joined: Wed Apr 21, 2010 6:21 am
Location: Iowa

Postby Tehrasha » Wed Jan 02, 2013 12:34 am

Linux definitely has CPU usage measuring capability. GPU usage I am not as certain of. I typically judge that by how fast the graphics card fan runs. :)

Fran
Posts: 4
Joined: Tue Jan 01, 2013 12:47 pm

Postby Fran » Wed Jan 02, 2013 1:38 am

Hi,

As I told you 'top' Linux command shows similar CPU activity on both cases.

I honestly appreciate your interest, but I asked this question here with the hope that someone that has addressed similar problems -or at least with a similar configuration- could give me some straight forward advice, not for taking shots in the dark, an activity that I am able to do by myself.

Bests,

Pi x Om
Posts: 9
Joined: Tue Dec 25, 2012 2:33 am
Location: space

Postby Pi x Om » Wed Jan 02, 2013 2:45 pm

Moderator's Note:

This post was deleted due to its lack of useful info and bad attitude. Let's all play nice!

MrJimbob
Posts: 1
Joined: Mon Jan 28, 2013 2:21 pm

Similar issue

Postby MrJimbob » Mon Jan 28, 2013 2:25 pm

I'm having similar results, running:

Blender 2.65
i7 2720QM
Nvidea GTX 460M

Same render speed using GPU / CPU.

I'm not convinced it is actually using the GPU - anyone have any ideas on how to check this?


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