Forum

Author Topic: Unable to get Photoscan to recognize more then 36 cores  (Read 4251 times)

Maximus

  • Newbie
  • *
  • Posts: 3
    • View Profile
Unable to get Photoscan to recognize more then 36 cores
« on: September 29, 2015, 03:44:35 PM »
We recently purchased a dell server with 36 physical cores and 72 logical cores. The issue we are having is Photocan seems to only recognize 36 of the cores. I have tried messing with the process priority and disabling hyper-threading, neither of which allows Photoscan to see more then 36 cores.

Is Photoscan capable of using more then 36 cores or is that the max?

Does anyone know how to get Photoscan to use all available cores?

Thanks

Alexey Pasumansky

  • Agisoft Technical Support
  • Hero Member
  • *****
  • Posts: 14813
    • View Profile
Re: Unable to get Photoscan to recognize more then 36 cores
« Reply #1 on: September 29, 2015, 06:12:13 PM »
Hello Maximus,

In the following post you can see the benchmarks of PhotoScan on 80 core system:
http://www.agisoft.com/forum/index.php?topic=1907.msg10223#msg10223

Do you see all 72 cores in task manager / system monitor when Hyper Threading is enabled?
Best regards,
Alexey Pasumansky,
Agisoft LLC

Maximus

  • Newbie
  • *
  • Posts: 3
    • View Profile
Re: Unable to get Photoscan to recognize more then 36 cores
« Reply #2 on: September 29, 2015, 08:15:02 PM »
Thank you for the follow up.

Yes we do see all 72 cores in task manager / system monitor.

Under the Photoscan preferences, OpenCL tab, the software is only showing 36/36 active CPU cores.


Wishgranter

  • Hero Member
  • *****
  • Posts: 1202
    • View Profile
    • Museum of Historic Buildings
Re: Unable to get Photoscan to recognize more then 36 cores
« Reply #3 on: September 29, 2015, 11:48:34 PM »
Just run some small benchmark and see the task manager if all cores are used.

Have dual or Quad CPU setup = what CPUs ?
What sort of Windows you have there ? = because win have limitation on max cores per system 
----------------
www.mhb.sk

Maximus

  • Newbie
  • *
  • Posts: 3
    • View Profile
Re: Unable to get Photoscan to recognize more then 36 cores
« Reply #4 on: October 02, 2015, 08:28:09 PM »
Under task manager I do see 36 cores with 72 logical processors available.

When I begin to align photos and build meshes with AgiSoft, 36 of the cores go to 100%, while the other 36 logical processors sit idle.

We are running Windows Server 2012.

Thanks

Wishgranter

  • Hero Member
  • *****
  • Posts: 1202
    • View Profile
    • Museum of Historic Buildings
Re: Unable to get Photoscan to recognize more then 36 cores
« Reply #5 on: October 03, 2015, 12:42:59 PM »
can post screenshot of the utilization CPUs when aligning ??

if have real 36 cores and 72 with HT then using "JUST" the 36 cores is OK, as the HT can speedup max 10-15% in ideal cases AND when have 6-8 cores altogether.. but mostly and not only in agi it will decrease the speed of sw. Having many cores is not every time the best solution you get intro problems with efficiency of CPU buses and etc...

Highly recommend DISABLE Hyper Threading  in BIOS on this 36 real core sytem !!!
----------------
www.mhb.sk

Mossberget

  • Newbie
  • *
  • Posts: 1
    • View Profile
Re: Unable to get Photoscan to recognize more then 36 cores
« Reply #6 on: March 02, 2016, 09:21:33 PM »
Couldnt all this be related to how windows handles system with more than 64 cores?
https://msdn.microsoft.com/en-us/library/windows/desktop/dd405503(v=vs.85).aspx

I am also running a system with dual 18 cores cpu, and I would say that turning of hyperthreading really isn't an option due to performance loss in other applications that recognizes the 72 cores.