Having the Operating System and applications on their own partition and the data on its own partition is a safer configuration and usually adds performance. Partitions can become corrupt over many reasons, but a lot of those reasons have to do with application or OS corruption. By keeping those on a separate partition, the corruption of the OS partition minimizes it hurting the data. If available, it is even better to have the OS and applications on their own drive and not on the same array. This helps with performance since data read/writes are separate from the OS/application read/writes. A good configuration on a Mac is to have a 4 drive array and a 5th separate drive with OS and applications on it. Then you keep a carbon copy clone of the OS on the array so that if the OS corrupts, you can just carbon copy clone it back to a new drive and you're off and running. Keep in mind the best RAID configuration for databases is RAID10.
In general, all hardware recommendations for Windows are equally as good for the Mac, but the Mac just has less hardware options. My favorite small business configuration of a Mac is to have a Mac Mini with two drives and maxed out RAM. The first drive has the OS and applications and the 2nd drive is the Time Machine backup. Then I connect a very fast Pegasus RAID10 Thunderbolt drive for the data, plus a carbon copy clone of the OS/application drive. While the Mac Mini is a consumer level machine, it actually performs really well with a RAID as fast as the Pegasus and there is no beating Thunderbolt technology for speed.
Hopefully the new Mac Pro will come out this year with Thunderbolt and the Mac will have a better server solution.
Thanks Taylor. This is exactly what I was looking for.