2 Replies Latest reply on Sep 14, 2010 7:19 AM by himanshu.gautam

    Is there any limitation to work-group quantity ?


      Is there a max number of work-group quanity for given device ? If yes ,how to query the max number?

      I can't find anything about querying max number of work-group quanity in the table of param_name of clGetDeviceInfo() function.

      Thanks !

        • Is there any limitation to work-group quantity ?

          From my reading of the OpenCL spec, the max global index in any dimension is 2^32-1.

          The spec states that an error will be returned when a global work size is specified that is bigger than the size_t type on the device (see page 133 of the OpenCL 1.1 spec).




            • Is there any limitation to work-group quantity ?

              hi all,

              As per spec there is no limit on the number of workgroups each device need to support.Obviously we cannot exceed 2^32-1 as the global thread id would not be representable in 32 bits.

              I tried to create a test program & it ran successfully for 2^25 workgroups.After which it failed due to the lack of system resources.

              So I think Gpus can execute as many workgroups in round robin method as system resources allow.The only upper limit being 2^32-1.

              I hope there are no more issues regarding this topic anymore.