https://www.truenas.com/community/resources/whats-all-the-noise-about-hbas-and-why-cant-i-use-a-raid-controller.139/ - HOWEVER, dedicated PCIe bandwidth ensures consistent performance - using a **SATA HBA** like the **LSI 9211-8i** can increase your **total storage throughput**, because it bypasses the **motherboard chipset's bandwidth limitations** - The 6Gbps advertised speed refers to the SATA III bandwidth for each port, while the 4GB/s PCIe 2.0 x8 bandwidth determines the total throughput of the HBA. - This provides a theoretical bandwidth of: PCIe 2.0 x8 = 4GB/s (32Gbps). - This bandwidth is **dedicated to the HBA** and is independent of the motherboard chipset's shared uplink (the **4GB/s limit** on the B550 chipset). - Therefore, the HBA provides an additional 4GB/s for storage. - Many HBAs support TLER (Time-Limited Error Recovery), which improves data integrity in RAID or ZFS environments. - Use an HBA if: - Run out of onboard SATA ports - Total throughput exceeds the SATA controller's connection to the CPU. This differs per motherboard and depends on the PCIe generation and the number of PCIe lanes the SATA controller has been assigned to. - If you connect to the machine via 1Gb LAN and your network is saturated way before the SATA controller. - If you run a NAS like TrueNAS virtualized and you want to pass the SATA controller to the VM instance. You can't do that with the motherboard SATA controller. (not needed if running TrueNAS bare metal) - Want to use SAS drives