Not everyone is aware of the fact that not all data types are supported in SSAS cubes / models. If you use one of the data types that are not supported by SSAS, SSAS will cast all your unsupported data types to supported data types when the cube is being processed.

This will cause your cube processing time to increase. And you will use more CPU than necessary.

Microsoft has provided a list of supported data types here

To avoid these kinds of problems there are several things you can do.

• Use views as source for your cubes. Then cast the values in these views. SQL Server is better than SSAS to cast values. And it is more likely that your SQL Server has more power that your SSAS server.
• Make sure your DWH only uses supported SSAS data types. But that’s not to likely is it?