GPU processing during the modeling and settings

[an198317]

Hi all,
I am curious about how much the GPU is involved in the modeling process. I can see during the dense point cloud step the GPU is used for computing. But during the mesh generation which is the most heavy computing process, I didn't see a lot of GPU involvement. So I am curious about during what the step(s) GPU is really used for processing?

And also what should I set up the OpenCL appropriately to optimize the speed? My workstation has 12 CPU cores, and Quadro 4000 has 8 cores based on PhotoScan OpenCL interface. Based on the OpenCL interface suggestion, deactivate one CPU core (using 11 of them) will use all Quadro 4000 8 cores?

Thanks,

[David Cockey]

GPU is not used during Align Photos.

GPU is used heavily during Reconstructing depth portion of Build Dense Cloud.

GPU is not used during Build Mesh.

GPU is not used during Build Texture.

With I7-3770 CPU (4 cores / 8 virtual cores) and Radeon HD 7770 GPU best performance is with 6/8 "Active CPU Cores". However during Align Photos 100% of all 8 virtual cores are used.

[mwittnebel]

Is there a possibility that Photoscan could also use GPU for more steps than Build Dense Cloud, in the near future ?

This would be a huge Performance upgrade for the Software.

[an198317]

That's what I would hope PhotoScan Pro can change....

[Lambo]

I am confused since I have seen this a couple times now, people saying that the build mesh step is the most heavy computing step? I keep seeing the dense cloud generation to be the most intensive on my side. Even by using the GPU that is much more powerful than the CPU it takes much longer than the mesh generation.
Am I the only one seeing this?
Leo

[David Cockey]

Current project has 250 to 750 photos per chunk. Medium setting for Create Dense Cloud results in 1 million to 7 million points per chunk, and takes considerably longer then Build Mesh.

[Patribus]

Hello,

although the infos given in the former posts seem quite clear, there is something I do not understand.

I'm working with an I7-2770 CPU (4 cores / 8 virtual cores) and a GTX 660 graphic card.

First I disabled 1 CPU core. When starting the depth reconstruction, no GPU activity takes place.
OK, so I thought, that has to do with the virtual cores, meaning that in practive I have to disable 2 cores. Restarted depth reconstruction, but GPU activity is still at 0%.

Now, what am I doing wrong, or what did I understand wrong?

depth reconstruction & dense point cloud generation should happen with GPU, or is it only the DPC generation?

If the first case is correct, than why does PS not use the GPU?

thanks for any hint

[sitzsack]

I would be interested in the same question... I use the GTX 770 though, also i7

[Alexey Pasumansky]

Hello Patribus,

PhotoScan uses every OpenCL supported device that is checked on in the corresponding tab of PhotoScan Preferences window.
Note that if you are using Windows Remote Desktop to connect to another machine the list of OpenCL devices will be likely empty and PhotoScan would not be able to use GPUs installed on remote computer.

[Patribus]

Hello Alexey,

I do indeed use TEamViewer as remote desktop service. But my OpenCL devices are listed in PS and respectively 'activated'.
So I would expect them also to be used.
But my GPU  remains unused.

Some other possible reason for this?

PS: just added a screenshot of my preferences.

[mobilexcopter]

Hello Patribus,

I missed the tool with one you are checking GPU usage. Can you please share the method?

Best regards,

Alex

[Patribus]

Hello Patribus,

I missed the tool with one you are checking GPU usage. Can you please share the method?

Best regards,

Alex

I just search for GPU monitor and found some widgets for windows (7 in my case) which show some (or all) parameters of my graphic card (T, Usage, Fan activity, MEmory usage, etc.). When I scroll in the browser I can see how the activity of the GPU goes up from 0% to 1% or 2%. The rest of the time it's at 0%

[Alexey Pasumansky]

Hello Patribus,

Could you please also check the console output in PhotoScan? If the GPU is used you'll see lines starting from [CPU] and [GPU] during depth maps estimation process.

[mobilexcopter]

Can you share the widget name?

I suggest you do a Bulild Dense Cloud on a dataset of 100+ photos with OpenCL enabled and another with disabled and compare the time. That is, if you can enable it now. 

If you would like to test the GPU, try the GPU Shark utility. Don't know if it exact, but it shows extended usage of the GPU and temperature rising. 

Best regards,

Alex

[Patribus]

Hello Patribus,

Could you please also check the console output in PhotoScan? If the GPU is used you'll see lines starting from [CPU] and [GPU] during depth maps estimation process.

Yes, the lines are present.
Just strange that no activity appears in the gpu monitor.