Large service area on SDC data can be done by increasing the cache size that SDC uses.To do this, add the following key:HKEY_LOCAL_MACHINE\SOFTWARE\ESRI\SDC\Network\CacheSize = UINT value in KBThe default value is 16MB or 16384. So set it to a larger value like 100000 in decimal.I tested this on a 9.2/sp3 machine with 512 MB RAM and the polygons were generated in38 minutes.Also note that ArcMAP does not crash in 9.3 with the default settings and the service areapolygons are generated.