These are used in servers and NAS devices. But why would it really be necessary?
- Is it mostly to offload the RAID management and calculations to a different CPU than the one from the machine? Or does that matter more for a server that has many more tasks than a NAS?
- Aren't the SATA (or SAS if there exist any) ports on the motherboard sufficient if it covers the number of drivers you need? They each work at at least 6 Gb speed for SATAIII? And the load on the CPU for RAID calculations probably is not that high?
- I know that one with a cache and battery increases storage reliability in the case of power losses. But don't a UPS for a server/NAS already cover that field?
- Using BTRFS or ZFS for storage reliability in a RAID environment, would this make the controller card quite useless except for being able to have more ports and offloading RAID activity?