Very slow simulation run

Hello,

I have an email into support already, but I might as well describe the problem here just in case anyone else has run across it:

I am building a model of a large assembly building, and I will have about 12000 occupants by the end. I have all the geometry set and all the occupants are placed in the appropriate rooms. When I try to run the simulation, "run time" runs at real time for about the first 40 seconds, then slows to about .2 or .1 seconds per second. "Sim Time" never starts, after about 30 minutes of waiting. I am used to the program churning out calculations in a minute or two, even for about 4000 occupants. Has anyone run into the strange time problem in their travels with this program?

The DXF files I used for the background were quite large (100000 objects or so), so I deleted them after finishing the geometry, just in case that was the snag. This made the "run time" run normally until the 60 second mark, but then it began the same problem of moving slowly. Is the model just too large for the software to handle?

Is there some way of increasing the amount of memory the program can use, in case that is the issue?

Thanks for the help!