Why IT mode?

IT mode (Initiator-Target) exposes each disk directly to the OS, with no RAID layer in the way - exactly what ZFS, TrueNAS and Unraid want so they can see SMART data and manage the array themselves. Many cards ship in IR/RAID mode and must be crossflashed to IT firmware first. The reference below flags which cards ship IT-ready and which need a flash.

Card Chipset Ports PCIe IT mode Firmware ZFS
LSI 9305-24i SAS3224 24 PCIe 3.0 x8 Ships IT P16 16.00.12.00
LSI 9305-16i SAS3216 16 PCIe 3.0 x8 Ships IT P16 16.00.12.00
LSI 9300-16i SAS3008 x2 16 PCIe 3.0 x8 Ships IT P16 16.00.12.00 (flash BOTH chips)
Dell HBA330 SAS3008 8 PCIe 3.0 x8 Ships IT Dell IT firmware (ships flashed)
Dell PERC H330 SAS3008 8 PCIe 3.0 x8 Crossflash → HBA330 / 9300-8i IT P16 16.00.12.00
Lenovo N2215 SAS3008 8 PCIe 3.0 x8 Crossflash → 9300-8i IT P16 16.00.12.00
LSI 9300-8i SAS3008 8 PCIe 3.0 x8 Ships IT P16 16.00.12.00 (9300_8i.bin)
HP H220 SAS2308 8 PCIe 3.0 x8 Crossflash → 9207-8i IT P20 20.00.07.00 (9207-8i.bin)
LSI 9207-8i SAS2308 8 PCIe 3.0 x8 Ships IT P20 20.00.07.00 (9207-8i.bin)
LSI 9217-8i SAS2308 8 PCIe 3.0 x8 Crossflash → 9207-8i IT P20 20.00.07.00 (9207-8i.bin)
LSI 9201-16i SAS2008 x2 16 PCIe 2.0 x8 Ships IT P20 20.00.07.00 (both chips)
Dell PERC H200 SAS2008 8 PCIe 2.0 x8 Crossflash → 9211-8i IT P20 20.00.07.00 (2118it.bin)
Dell PERC H310 SAS2008 8 PCIe 2.0 x8 Crossflash → 9211-8i IT P20 20.00.07.00 (2118it.bin)
IBM ServeRAID M1015 SAS2008 8 PCIe 2.0 x8 Crossflash → 9211-8i IT P20 20.00.07.00 (2118it.bin)
LSI 9211-8i SAS2008 8 PCIe 2.0 x8 Ships IT P20 20.00.07.00 (2118it.bin)
LSI 9211-4i SAS2008 4 PCIe 2.0 x8 Ships IT P20 20.00.07.00 (2118it.bin)

Ports = internal (+ external where present). "Crossflash" cards need IT firmware before ZFS/TrueNAS will see disks directly.

HBA guides