2008版一個時域求解錯誤

先是一個警告：
The current settings will probably lead to a very long simulation time.
You may improve the simulation speed by:
1.checking the frequency range and units settings
2.extending the simulation frequency range
3.checking the mesh to avoid very small mesh steps
然后是這個錯誤：
Calculation is aborted due to port memory exception. Please reduce number of ports or simulation duration
不知道這是什么原因引起的？
我算的諧振腔，當頻率范圍2.7~3G時不出現上面的警告和錯誤
而當我減小頻率范圍時就會出現上面的警告和錯誤，為什么時域求解時，頻率范圍小會增加仿真時間？
不知道這個跟2008版里新增的adaptive port meshing功能是否相關？
謝謝！