RAID VDISK vs Windows Partitions for SQL server

Hi,

I am in the midst of setting up a new SQL server(mssql 2005) with two instances on Server 2k8 R2. Below are the specs of my server.

HP DL380 G7
2 x E5649(Hexacore 2.53GHZ)
16GB of RAM DDR3
4 x 600GB SAS 10k drives


So what I would like to do is have one Vdisk with Raid 5(100GB) for O/S, and the rest in Raid 10 for DATA.

I would like to have 4 logica

l drives/partitions(2 for Data for each instance and 2 for Logs for each instance)

So my question is should I carve out the data drive using windows partitions or making Vdisks from the raid controller?

I have heard by making multiple Vdisks, you are pretty much splitting I/O and killing the I/O on your server, and I am in desperate need of IOPS since it is a SQL server.