There are two task execution modes: parallel and serial.
Parallel execution will start all tasks at the same time when a new operation begins. For instance, when extracting ten archives, all ten extract operations will be started simultaneously. Parallel execution mode is recommended only for powerful computers, and can improve performance on multi-processor systems with good memory.
Serial execution will start tasks one by one, wait for the completion of each running task, and then start the following task. When extracting ten archives, there will be ten steps to the extraction; as each file finishes extraction, another will start extracting.
To set task execution modes:
Click Options, then click Technical.
Check Parallel Mode for parallel execution and Serial Mode for serial execution.
Click OK to apply the settings.