Performance Profiling

GridLAB-D™ has a performance profiler built into the core that allows users to generate an analysis of the simulation performance. Additional measurements on class and module performance are collected to perform module/class performance analysis. The performance analysis is based on the quantitative measurements collected while the simulation is running. These measurements are then used to estimate the overall performance metrics for both the core and the modules.

Core profiles

The key measurements of the core performance analysis shown in Table 1 and the performance metrics are shown in Table 2.

Table 1: Core performance measurements

Property	Description
N_objects	The total number of objects in the model.
N_threads	The maximum number of concurrent threads used by the simulation.
T_total	The total elapsed wall-clock time of the simulation.
T_sync	The total wall-clock time spent in object synchronization. This is the cumulative sum of the time spent in each object's synchronization functions.
T_sim	The total elapsed simulation time of the model. This is the simulation stop time minus the simulation start time.
N_sync	The total number of sync passes completed. The sync count is incremented whenever an object synchronization is requested.
N_step	The total number of timesteps completed. The step count is incremented each time the clock advances.
N_lock	The total number of locks requested. The lock count is incremented each time a lock is requested.
N_spin	The total number of lock spins completed. The lock spin is incremented each time a lock is requested but denied.

Table 2: Core performance metrics

Metric	Formula / Value Description
Total objects	N_objects
Parallelism	N_threads
Total time	T_total
└─ Core time	T_total - T_sync
└─ Model time	T_sync
Simulation time	T_sim
Simulation speed	(T_sim × N_objects) / T_total
Syncs completed	N_sync
Time steps completed	N_step
Convergence efficiency	N_sync / N_step
Memory lock contention	N_lock / N_spin
Average timestep	T_sim / N_sync
Simulation rate	T_sim / T_total

Module/class profiles

The class profiles are much simpler than core profiles because they only present the amount of time spent overall in each class, the fraction of the total time spend in the class, and the time spend in the class per instance of the class.