[dba-SQLServer] Advantages to separate databases

I have a situation where I import tens of millions of records of raw data
(as I call it) into SQL Server.  I turn right around and send the name /
address out for processing and when I get that back I import that back into
SQL Server in a separate table.  Is there any advantage to bringing that
second table (addresses) back in to the same database that I have the raw
data in?

The way I use the data is that I add a PK long autoincrement to the raw data
table and export that with the name / address.  Thus when the data comes
back in from address processing each record coming back has a PKID that
matches a record in the raw data table.  When I build queries I often do a
join on PKID between raw and address and then select fields from both.  

It appears to me that having them in separate database files is actually an
advantage in many ways.  For one, the data in the raw data file can be
archived once and never touched again as far as backup is concerned.  The
data in that table never changes.  Also it seems that I might be able to
place the two files (raw and address) on separate machines and get some
parallelism going in processing where clauses etc.  It may in fact be
exactly the opposite and I would NOT want to set the two databases on
separate machines though, I am certainly no expert on anything SQL Server
related.

Any thoughts on the pros and cons here?

John W. Colby
Colby Consulting
www.ColbyConsulting.com