Biztalk performance issue

Hi, I'm a newbie at Biztalk.

 I have a project that requires
me to load data that is stored in an xml file to two tables on a MSSQL
server. Now I've created my orchestration and have my receive and set
ports all set. The setup works but for very small sets of files. For
example, If its processing 100 xml messages, Biztalk is able to process
all the information in no time. However, it gets slower and slower when
there are more files. For instance if I had 6000 xml messages, it would
slow down to a crawl and I estimated it would take a few days to
process all the information. My questions are:

 
1. Why is there such a huge drop in performance when the number of messages are increased?

2.
What would be a possible solution to this? I am guaranteed to have
close to 30,000 xml messages to process, since they are generated by
the HIPAA accelerator which is processing 834 files that we get from
our client.

3. Do I need to add some external program to
basically move small set of messages for my project to consume?
(Because processing of a 1000 messages takes less time than the
processing time for 6000 messages)

 
Oh and just to let you
know, the orchestration is a sequential convoy. There is a reason for
this because each time my sproc is called, it is inserting the data
into two tables (but one table is tied to the other table by its id
field). I know this is a slow way but it still does not explain why the
performance drops significantly when the number of messages is
increased.

Thanks in advance

– George John