Multi-Threading and Tire Models

Since computing tire forces and moments during a vehicle simulation is one of the most costly tasks, multi-threaded execution of tire models on a multi-core computer can substantially reduce the clock time for a simulation.

For a vehicle with four tires, multi-threaded execution typically reduces the clock time to complete a simulation between 30 to 40 percent. Total CPU time for multi-threaded execution, however, is actually larger than single threaded execution due to the overhead of multi-threaded execution.
The CDTire and FTire models offer multi-threaded execution with MotionSolve, while the MF-TYRE, MF-SWIFT, and RMOD-K models do not. The means to enable multi-threading for CDTire and FTire do differ, therefore each method is described in the table below:
Tire Model Multi-Threaded Enabling Multi-Threading
CDTire YES The CDTire.ini file controls multi-threading for CDTire. To enable multi-threading, set the maximum threads in the parallel block to a number greater than one.

For example:

[Parallel]

MaxThreads=4
FTire YES Multi-threading is controlled by the environment variable NUSOL_MT_TIRE.
  • NUSOL_MT_TIRE = 1 (Multi-Threaded execution
  • NUSOL_MT_TIRE = 0 (Single Threaded execution)
With multi-threading enabled, FTIRE throws one thread for each tire.
MF-TYRE

and

MF-SWIFT		 NO Not Applicable
RMOD-K NO Not Applicable