User Guide

Contents

Setting Concurrency Specification

The concurrency specification is a list of the number of threads on which the graph is run. To set the concurrency:
  1. Open the
    Preferences
    window.
  2. Go to the
    Scalability
    TBB
    category.
  3. Set the list in the
    Concurrency Specification
    field in the
    1,
    a
    -
    b
    :
    n
    format, where:
    • 1
      is the serial run. Because the speedup is estimated with respect to a serial run of a graph, by default, all graphs are first run serially before running on multiple threads. The addition of 1 is merely symbolic and informational, as its omission has no effect on the list.
    • a
      is the starting number of multiple threads.
    • b
      is the ending number of multiple threads.
    • n
      is the step size.
    preferences dialog box
The default end value is the number of cores on the system and the default step size is a quarter of this value. The end value is always included in the list, even if it is not a direct multiple of the step size.
As an example, on a 32-core system, the default is
1,8-32:8
. This results in the list
1,8,16,24,32
, as shown below.
analytics report for 32 core system
Other supported formats are
a,b,c
or only
a
if you want to see the speedup for only one set of threads.
You can also combine formats. The following shows some valid concurrency specifications:
  • Range without a step size:
    16-64
    yields
    1,16,32,48,64
  • Range with a step size:
    16-64:8
    yields
    1,16,24,32,40,48,56,64
  • Single value:
    16
    yields
    1,16
  • List of values:
    16,32,64
    yields
    1,16,32,64
  • Mix of range and list:
    16-64,40,48,56
    yields
    1,16,32,40,48,56,64

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