I think this has more to do with hardware incompatibility than unraid, but here it goes:   I have an Intel DQ77MK mobo (Q77 chipset, basically server grade Z77) with 10 drives (ultimately it'll become 12 once I add another SSD for cache pool, and an extra parity drive). Long story short, with a GPU (1660 Ti) installed for PLEX, the only other ports I had available for a SATA expander were a PCIe x4 or x1. That basically ruled out any usable LSI SAS cards which are mostly x8 for their 8