Expansion cards are fantastic in that they are inexpensive ways to improve the versatility of a host system. This could be network-attached storage (NAS), a desktop PC, or a home lab server. Host Bus Adapters (HBAs) are particularly great for DIY servers where consumer-grade motherboards don’t provide the right level of redundant array of independent disks (RAID) or enough SATA ports.
It doesn’t really unlock features that weren’t previously available on the motherboard, but it provides new hardware that sits between the board and storage drives. This allows them to expand the capabilities of the motherboard’s built-in storage controllers, most of which aren’t designed for more intensive applications like big data storage and self-hosting content. They’re great when used appropriately, but you could encounter times when you simply need more.
HBAs come in all shapes and sizes, consisting of a few SATA ports to advanced hardware-based RAID acceleration. It all boils down to what you require from such a device. For me, I built a new custom NAS, replacing a six-bay TerraMaster I relied on (and outgrew) with TrueNAS SCALE. The new build used a standard B650 motherboard with just four SATA ports. For someone who needed more than six drives to be connected, it was time to think outside the box.
Not used an HBA before?
It’s a miracle for some home labs
HBA is a card that connects the CPU and motherboard to SATA, Serial Attached SCSI (SAS), and other storage devices, but what does that mean, exactly? Using an HBA expansion card exposes drives directly to an operating system, much like they would if directly connected to the motherboard’s controller through available PCB ports. Your motherboard likely has between two and six SATA ports.
Consumer motherboards you’d find inside desktop PCs obviously don’t have as advanced controllers as better-equipped solutions. This is fine if you’re only connecting a few drives to the system and wish to use software RAID, but when needing to interact with SAS or load up a NAS OS with more than 10 drives, things can quickly get out of control. That’s where the HBA comes into play, offering countless channels with a single PCI slot.
The best part of an HBA is that it acts much like an external capture card for recording gameplay by offloading much of the work to the card itself. Instead of bogging down the motherboard, CPU, and OS with more work to handle, the HBA passes all the commands to the drives themselves, which is slightly different from how a motherboard’s SATA controller works.
AHCI/SATA ports on your motherboard are tied to chipset lanes, which are often listed on specification lists. There’s usually no hardware RAID, either with software or firmware-based RAID solutions present as a stopgap. Not many people will run drives with RAID, so it’s not really a complaint for manufacturers — consumer-grade boards simply don’t need hardware RAID, not unless we’re using one for the home lab.
HBA cards are the most underrated home server upgrade
More storage for your server can come with headaches, but a SAS HBA could make things easier.
RAID isn’t always the same
More ports, more drives, more RAID
Motherboard AHCI/SATA controllers won’t offer the same levels of performance as dedicated hardware for the task. It’s not like the audio codecs, which are actually pretty solid on many modern motherboards and can be used for most tasks involving media. These storage controllers are limited by chipset lanes and port count. Most consumer boards top out at four to six SATA ports, which quickly becomes restrictive in a serious NAS build.
TrueNAS, in my case, is what powers our NAS. Using ZFS, which handles redundancy, parity, caching, and integrity at the filesystem level, a HBA card like the 9305-16i offers direct access to as many drives as possible. Dedicated RAID controllers will come rocking dedicated controller chips, memory, and firmware for reducing overall system load. There’s no real wrong answer here, as the right RAID type and level will depend entirely on your storage requirements. HBA cards are for adding more drives, which is precisely what I needed.
By installing the HBA, each drive is passed directly to the operating system without being abstracted behind a hardware RAID layer. Instead of the motherboard limiting pool design, TrueNAS can see every individual disk and build RAIDZ configurations across a much larger number of drives. More drives unlock better RAIDZ2/RAIDZ3 layouts, improved performance through multiple vdevs, stronger fault tolerance, and greater long-term scalability for the NAS.
The upgrade isn’t about offloading RAID logic to the card, but removing the motherboard’s storage ceiling and letting ZFS operate the way it was designed to with enhanced RAID support. Moving from limited onboard SATA ports to a SAS HBA completely changed what was possible. Instead of being constrained by four ports, I could attach a large pool of disks and design the storage layout around reliability and performance — not motherboard limitations.
