Developer Guide

Contents

Performance Considerations

To get the best overall performance of the DBSCAN algorithm, do the following:
  • If input data is homogeneous, provide the input data and store results in homogeneous numeric tables of the same type as specified in the
    algorithmFPType
    class template parameter.
  • If input data is non-homogeneous, use AOS layout rather than SOA layout.
  • For the output assignments table, use a homogeneous numeric table of the int type.
DBSCAN may show different performance depending on
memorySavingMode
flag:
  • When flag is set to false, all neighborhoods can be computed and stored together, which may give better parallelism utilization and, therefore, better performance;
  • When flag is set to true, neighborhood computation is done during the algorithm execution. With rather small amount of simultaneous queries, you get worse parallelism utilization and, therefore, worse performance.
When total size of all neighborhoods is larger than the amount of memory available, usage of
memorySavingMode
=true flag can be the only option.

Product and Performance Information

1

Intel's compilers may or may not optimize to the same degree for non-Intel microprocessors for optimizations that are not unique to Intel microprocessors. These optimizations include SSE2, SSE3, and SSSE3 instruction sets and other optimizations. Intel does not guarantee the availability, functionality, or effectiveness of any optimization on microprocessors not manufactured by Intel. Microprocessor-dependent optimizations in this product are intended for use with Intel microprocessors. Certain optimizations not specific to Intel microarchitecture are reserved for Intel microprocessors. Please refer to the applicable product User and Reference Guides for more information regarding the specific instruction sets covered by this notice.

Notice revision #20110804