"gpu_threads_conf" : [
 // gpu: Cayman memory:1663
  // compute units: 24
  { "index" : 0,
    "intensity" : 874, "worksize" : 20,
    "affine_to_cpu" : false, "strided_index" : 1, "mem_chunk" : 2,
    "comp_mode" : true
  },
  // gpu: Cayman memory:1663
  // compute units: 24
  { "index" : 1,
    "intensity" : 874, "worksize" : 19,
    "affine_to_cpu" : false, "strided_index" : 1, "mem_chunk" : 2,
    "comp_mode" : true