This listing is for a PCI NVME card for HP Z*40 (HP 240, 440, 640 & 840) systems. The card includes four slots for NVME drives which can be seen on most operating systems as four separate NVME drives. The card is populated with 4 256GB NVME drives that have been used very little. The card is only offered for use with Proxmox, Windows or with ZFS raid for Linux Mint customized to the buyers specs.
The most common desktop operating systems also have some working implementation of software raid which improve read/write speeds and redundancy or to support a combination of both. Software raid varies depending on the operating system and there are also reasons why it would be beneficial for a desktop OS.
Proxmox (Linux) - Virtual Environments like Proxmox recommend using raid to improve the performance of the Virtual operating systems that are installed. Setting up software raid rather trivial so most users can do it themselves by simply selecting the type of raid array to create before installing.
Linux Mint - Software raid should work on almost any Linux variant, but I only tried it on Linux Mint. Linux can be setup to boot from a raid array or an array can be setup on a separate partition for use with certain files and file processing. There are a few ways that software raid can be setup, but ZFS would use used by default
Microsoft Windows 10-11. Earlier versions of Windows may support software raid, but because they are longer supported we just stick with the newest supported versions. Windows doesn't support booting from a software raid disk so one of the disks would have to be setup as the boot disk there is no other disk that can be setup to boot from. The raid array would appear as a separate disk or mount point.
One common scenario that might require a multi cor Xeon system would be for video editing where high resolution video and files can be rather large and there will be less of a bottleneck with processing because of read/write speed of the drive.
Raid 0 provides striping across multiple disks for speed as only a portion of the file is copied to each disk, but if one disk fails the entire array fails.
Raid 1 mirrors date on two disks for redundancy.
Raid levels up to 10 have parity checking
Raid 10 is a combination of Raid 0 and Raid 1 for speed and redundancy.
Software raid will have at least Raid 0 and Raid 1 and the other offerings will vary with the operating system.
If you have any questions feel free to ask, but you will have do your own research on software raid as I don't have time to answer questions about how raid works because you don't want to do any research yourself.