One Large Raid vs Multiple Raids

Hello Everyone,

We have a MD3600F, it has a 12 600SAS drives, and I was hoping you can help me decide how to handle the Raid and Lun creation.
this san will store everything we have:
- VMware VM's
- SQL databases (about 5)
- Exchange database
- Users folders and profiles
- Archives

I was planning to create a large raid 10 array (all drives) and dump everything in it, but after some reading, it might be better to separate them and create several raid arrays, at least one for the DB's.

so my questions are:
- Is it better (performance wise) to break the Large raid to two/three smaller raids?
- If yes, will it perform better on a raid 1 (two drives, I can't spare more than two drives for the DB's) than on the large raid 10?


Thank you for your help and time.