You need to find out the differences between the two scenarios.
Add a PROC OPTIONS;RUN; to see if there are any difference in configuration settings.
OPTIONS FULLSTIMER; will help you see in more detail differences in resource consumption.
I presume that you run the exact same program, and it runs on the same machine. And in the same time of day?
If it's a multi-user server, you might want to see the overall resource usage (perfmon/task manager).
Data never sleeps