Some of the information supplied here may be used to relate to a system with similar configurations to mine, but because each person's system setup may be different, the findings here may not match the results from those other systems. The equations used and information about the SETI client comes from the work of both Roelof Engelbrecht and Lawrence Kirby. Lawrence made measurements on the SETI client to determine the amount of calculations the client produces based on the work unit's angle ranges. The graph above is what you get when you plot the angle range vs TeraFLOPs in a work unit. The big drop off in TeraFLOPs is due to the transition between equations at 0.2255 angle range.
TeraFLOPs are the total amount of calculations needed to complete a work unit.
Because of this, the run times for a work unit should actually mirror the number of TeraFLOPs for that work unit. As you can see, the run times are quite variable. The SETI client is usually running in the background while I am doing various tasks. Some CPU intensive applications such as pulling the team stats and preparing them daily, can lead to large variations in run times. Luckily, there is a way to relate the SETI work unit run times to the amount of TeraFLOPs needed to complete those work units.