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1663 Discussions

Xeon E5-2690 v3 doesn't report correct OpenCL Max Compute Units

allanmac1
Beginner
394 Views

Here's a puzzling situation.

Different drivers and architectures (x86 vs. x64) report a different "max compute units" value on a dual Xeon E6-2690 v3 workstation (2 x HyperThreaded 12-core Xeons).

The new Visual Studio Code-Builder "Platform Info Tree" reports 32 compute units on both the 1.2 and 2.1 devices (incorrect).

The older standalone _x86_ Code-Builder reports 32 on both the 1.2 and 2.1 devices (incorrect).

The _x64_ Code-Builder reports 48 on both the 1.2 and 2.1 devices (correct).

The Nsight OpenCL System Info window reports 48 on both devices (correct).

xeon_cl_1.2_x86.png

xeon_cl_2.1_x86.png

xeon_cl_1.2_x64.png

xeon_cl_2.1_x64.png

nsight_cl_system_info.png

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3 Replies
Jeffrey_M_Intel1
Employee
394 Views

Thanks for this report.  Some questions:

  • We've just released a new SDK (R3).  Do you still see the problem in the Visual Studio code-builder plugin with the latest R3 SDK version?
  • What version of Visual Studio are you using?
  • What info do you get from clGetDeviceInfo for CL_DEVICE_MAX_COMPUTE_UNITS?  (You can check with the Capsbasic sample.  Should be correct, but it will be helpful to verify.)

 

allanmac1
Beginner
394 Views

Jeffrey M. (Intel) wrote:

Thanks for this report.  Some questions:

  • We've just released a new SDK (R3).  Do you still see the problem in the Visual Studio code-builder plugin with the latest R3 SDK version?
  • What version of Visual Studio are you using?
  • What info do you get from clGetDeviceInfo for CL_DEVICE_MAX_COMPUTE_UNITS?  (You can check with the Capsbasic sample.  Should be correct, but it will be helpful to verify.)

 

  • This was with R3 installed.  The VS2015 code builder plugin only reports 32 compute units.  The EOL'd standalone Code Builder x86 also only reports 32 compute units.
  • VS2015 Pro
  • CL_DEVICE_MAX_COMPUTE_UNITS is what the Nsight System Info panel uses and it reports 48 units ... but is this related to x64 vs. x86?
Jeffrey_M_Intel1
Employee
394 Views

Thanks for the additional info.  Not sure if there is a relationship to x64 vs x86, but I've got this filed as a potential bug so we can continue looking from here.  Thank you for your help with making our tools even better.

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