Partitioning: Do we need multiple filegroups?

Question

I'm currently reading the SQL Server 2005 partitioning bible (i.e. Kimberley Tripp's whitepaper).

In it she states, "The schema always uses a function to [map to a filegroup]; if the function defines five partitions, then the schem must use five filegroups. The filegroups do not need to be different; however, you will get better performance when you have multiple disks and, preferably, multiple CPUs".

Now OK, I can see the benefit of using different filegroups from that but we are using a SAN so we're wondering whether a different filegroup for each partition is really necassary.

Questions are:

1) Is there any point in multiple filegroups when using a SAN?

2) Assuming the answer to the first question is "No", is there any point in multiple filegroups when there are multiple processors (we have 16)?

 

Thanks in advance.

 

-Jamie

 

UPDATE: Just come across another useful quote from the paper:

"SQL Server benefits from parallelizing an operation across partitions. In the case of storage alignment and multiple CPUs, each processor can work directly on a specific file or filegroup with no conflicts in data access because all the required data is on teh same disk. This allows more process to run in parallel"

That would seem to suggest the answer to my second question (above) would be "Yes".

 

Comments???