code: protected Comparator<OpenCLDevice> getDefaultGPUComparator() {
        return new Comparator<OpenCLDevice>() {
           @Override
           public int compare(OpenCLDevice left, OpenCLDevice right) {
              return selectLhs(left, right) ? -1 : 1;
           }
        };
     }
docs: NB, returns -ve for the better device.