====== Multithreading (the old way) ======

**Note:** this page applies to L3DT Pro 2.5.3.0 and earlier. Users of L3DT Pro 2.5.3.1 or later should refer to [[l3dt:userguide:multithreading|this user-guide page instead]].

===== Disabling multithreading =====

If you need to disable multithreading((...for instance, when it's not working properly...)), you may do so by downloading the text file below (DisableMT.patch.txt), and drag-and-dropping it onto the L3DT desktop icon.

^ Disable multithreading |{{http://www.bundysoft.com/L3DT/downloads/examples/DisableMT.patch.txt|DisableMT.patch.txt}} |

You need to restart L3DT for this patch to take effect.

Once you have disabled multithreading, L3DT will never automatically re-enable it, even  if you uninstall and re-install. To manually re-enable multithreading, see the next section.

===== Enabling multithreading =====

To manually enable multithreading, download the text file below (EnableMT.patch.txt), and drag-and-drop it onto the L3DT desktop icon.

^ Enable multithreading | {{http://www.bundysoft.com/L3DT/downloads/examples/EnableMT.patch.txt|EnableMT.patch.txt}} |

You need to restart L3DT for this patch to take effect.

Things to note are:
  - This script will have no effect on //L3DT Standard//, which does not support multithreading.
  - Multithreading is enabled by default in //L3DT Professional//, so this script will only have an effect if you have previously manually disabled multithreading (see previous section).

===== Controlling the core utilisation =====

If multithreading is enabled (see above), L3DT will auto-detect the number of available cores on start-up, and will allocate one calculation thread per core. If you would like to change the number of cores used (e.g. limit to three cores on a quad-core system), open the '//Settings->Local settings//' menu option, disable the 'Calc->ThreadManager->AutoDetectCoreCount' flag, and set the 'Calc->ThreadManager->MaxThreadCount' entry to the desired value. 

<note>The maximum number of cores currently supported by L3DT Professional is 8.</note>