Striping size

[Ayman Altounji]

I'm setting up Exchange 5.5 on a Compaq Proliant ML530 server. I have created 3 Arrays (operating system RAID1, logs RAID1, Exchange database RAID5).
I am wondering about the best Striping Size (Smart Controller) and Allocation Unit Size (Operating Sistem).
I've read that the best performance should be with the largest striping size and an Allocation Unit Size matching the size of I/O operations (depending on the application). Is this correct?
- What is the best striping size for a RAID 5 Array?
- What is the best Allocation Unit size for Exchange 5.5 Log partition and Exchange 5.5 databases?

Thanks in advance
Frigo Positivo