For loading, set txRate=500 in:
/opt/SPECjAppServer2004/config/run.properties
After loading, for run, switch it back to txRate=100.
Please see User Guide section 2.5 for details.
If your settings are correct, you should see 500 in the load log, for example:
Apps server is glassfish
Loading database with orders_injection_rate = 500
Loading Databases ...
INFO : IR supplied : 500
INFO : stepped IR : 500
STARTING loading of tables in the Corp domain...
Launching 1 threads to execute LoadCorp.loadCustomers() concurrently
Starting thread: Thread[CustomerThread-0,5,main] For range 1 - 3750000
...