Sql Server Destination In Memory (not The Usual Question)

All,

I've used the SQL Server Destination, and I know it is faster than Ole Db Destinations in some setups. I have read that this is due to the in memory transfer of data that happens from SSIS to the destination database. I haven't heard it explained in finer detail, and I am wondering if someone can confirm how this works.

My guess is that the SSIS server process handles loading the data into memory from the Source destination (I assume this does not have to be local). I'm guessing there must be some interprocess communication going on between the SQL Server process and the SSIS server process to do the transfer of data (please confirm this.) I know that the SSIS process and the SQL Server process must be loaded on the same machine. And in testing see that the process errors out with permission-like errors when SSIS is not on the same server as the destination. (Which I expect based on the documentation - this is not the source of my question.) Is there any sort of local disk activity that SSIS uses to cache the data or anything like that? Or is all of the resulting disk activity writes that occur in the SQL Server user destinaation database or temp database?

Any information you can provide on how the transfer of data occurs from the SSIS process to the SQL Server process would be very interesting to me. I use SSIS a lot and would just like to understand the mechanics there.

Thanks much (and Microsoft I would _really_ appreciate an answer from you guys if possible!)

dcb99