I too have never bothered with setting up a RAID configuration - I also believe it not necessary.
I would suggest a configuration with:
1) Primary Drive: A solid-state drive, to contain the OS, all applications (including plugins), with the Windows User Folders relocated to a different drive, so as not to fill up the SSD.
2) Data drives: at least 1 data drive, or if possible 2 or more data drives, that would contain Cakewalk Projects, Cakewalk Content, the relocated User Folders (Documents, Pictures, Music, Videos, Downloads, etc), and Sample Libraries. When Possible, house Cakewalk Projects, Cakewalk Content, and User Folders on 1 data drive, and then put the Sample Libraries on 1 or more additional data drives - depending on your budget. (My system has 1 primary drive that is a 240 GB solid-state, and 3 additional 2 TB data drives. That 3rd drive is used as an incremental backup location for my User Folders and for Cakewalk Projects that were worked on during the week. I have a 6 TB external USB 3 drive for full backups).
For whatever the worth, if possible you want to split data that is likely to be concurrently accessed, across multiple drives, to improve performance for reading and writing. Many motherboards come with 6 SATA connectors, so if you use 1 connector for the primary drive and another for the optical drive (CD/DVD), then you would be able to connect up to 4 additional drives without having to add an expansion card for additional SATA connectors.
With my system as configured above, I have no performance bottlenecks. The 240 GB solid-state drive was around $100-$120 at the time of purchase, and they are currently a bit less than that, if memory serves. Each 2 TB data drive ran me around $70-$80 at the time, maybe a little more. The 6 TB external USB 3 backup drive ran me around $180 at the time.
Backup your data files faithfully, or at some point you WILL get bit by the combination of a drive failure and either no data to restore, or non-current data available for restore. IF backups are done faithfully and properly, in MY opinion there is no need for a RAID setup.
So, for my system the drives and content are:
1) C: 240 GB solid-state drive. This is my primary drive. It contains Windows, and all applications, including plugins.
2) D: 2 TB data drive. It contains: Cakewalk Projects, Cakewalk Content (including Cakewalk Command Center download files), and User Folders.
3) E: 2 TB data drive. This drive contains Sample Libraries from Native Instruments Komplete 8 Ultimate, and additional Kontakt libraries that include commercial paid libraries and freeware Kontakt libraries.
4) F: 2 TB data drive. This drive contains the full download Sample Library content from my subscription to the EastWest Composer Cloud.
5) G: 2 TB backup drive. I make copies of Cakewalk Projects that were worked on during a given week, just to have a fast means of recovering one or all projec(s) as needed. This data gets wiped out after I do a full backup of my user folders and the Cakewalk Projects folder every week. I also backup my User Folders weekly, as well as the hidden AppData folder.
6) H: Optical drive - (CD/DVD)
7) I: 6 TB external USB 3.0 backup drive, for full backups.
Bob Bone