ZFS wants raw disks. A RAID controller hides each drive behind its own logic and hands ZFS a virtual volume, which blinds the filesystem to the SMART data and per-disk errors it exists to act on. The card you actually want is a SAS host bus adapter flashed to IT mode, which passes every drive through untouched. Onboard SATA runs out of ports somewhere past four to six drives, so the moment a pool goes wide the HBA is the part that decides whether the build is reliable or a resilver that never finishes.
Four things separate one card from another, and price tracks all four: the SAS generation (6Gb/s SAS2 versus 12Gb/s SAS3), the PCIe generation and lane count that set the ceiling for the whole card, the port count, and whether the card is tri-mode and can also drive NVMe. The five picks below run from a budget card for a pool of spinning disks up to a tri-mode card that will take U.2 NVMe. For the chassis and drives that go around one of these, the TrueNAS SCALE build guide and the NAS hard drive picks cover the rest of the parts list.
Bench notes taken on TrueNAS SCALE with the in-kernel mpt3sas driver, September 2026.
1. LSI 9300-8i (SAS3008): the default for most TrueNAS builds
This is the card most builds should buy. The SAS3008 controller gives you eight internal ports at 12Gb/s SAS3 on a PCIe 3.0 x8 card, split across two SFF-8643 connectors that each break out to four SATA or SAS drives. One card feeds eight disks with no expander in the path. Flashed to IT mode it presents every drive raw to ZFS, which is exactly what the filesystem wants. Pre-flashed cards run around $70 to $90; check the live price before you buy.
Why it wins: SAS3 headroom you will not saturate with spinning disks, a PCIe 3.0 x8 ceiling of about 7.9GB/s that eight SATA SSDs cannot exceed, and the widest driver and community support of any card here. The one thing to watch is provenance, because counterfeit SAS3008 chips turn up on the cheapest listings. That check is worth its own section further down.
2. LSI 9211-8i (SAS2008): the budget card for spinning disks
The homelab classic. The SAS2008 controller carries eight ports at 6Gb/s SAS2 on a PCIe 2.0 x8 card. The older silicon shows up in two numbers: SAS2 caps a single link at 6Gb/s, and PCIe 2.0 x8 caps the whole card at about 4GB/s. Neither ceiling matters for a pool of hard drives, which top out near 250MB/s each. Put SATA SSDs behind it and the PCIe 2.0 x8 aggregate is what bites first: eight of them at 550MB/s each is about 4.4GB/s, just over the card’s ceiling. The 6Gb/s per-link cap only becomes the bottleneck with 12Gb/s SAS SSDs, which negotiate down to SAS2 speed on this card. A genuine card flashed to P20 IT firmware runs around $60 to $80; check the live price.
Buy it only for spinning rust. For an all-SSD or mixed pool the 9300-8i costs a little more and removes the ceiling, which is the better spend. If you do buy at this tier, buy the genuine LSI card flashed to P20, not one whose firmware revision the seller cannot name.
3. Broadcom 9400-16i (SAS3416): sixteen ports without an expander
When a pool outgrows eight drives there are two ways up: put a SAS expander behind an eight-port card, or move to a sixteen-port card. The 9400-16i is the second path. The SAS3416 controller carries sixteen internal ports at 12Gb/s across four SFF-8643 connectors on a PCIe 3.1 x8 card, and it is tri-mode, so the same ports run SAS, SATA, or NVMe. For a 12 to 16 bay tower it is cleaner than an expander because there is one card, one driver, and no backplane to match. OEM P24 IT-mode cards run around $140 to $180; check the live price.
The tradeoff is the PCIe 3.1 x8 ceiling, still about 7.9GB/s, now shared across sixteen ports instead of eight. With hard drives that is irrelevant. With sixteen SAS SSDs you would feel it, which is the exact point at which PCIe 4.0 and the 9500 series start to earn their price.
4. Broadcom 9500-8i (SAS3808): tri-mode for NVMe and future pools
The newest of the group and the only one built on PCIe 4.0. The SAS3808 controller carries eight ports at 12Gb/s on a PCIe 4.0 x8 card, which roughly doubles the bandwidth ceiling to about 15.8GB/s. Tri-mode here means it will drive U.2 or U.3 NVMe drives off the same connectors as SAS and SATA, which no other card on this list does at full speed. Buy it if the pool has, or will soon have, NVMe, or if you want a card that outlasts two chassis. Expect around $245 to $270; check the live price.
For a pool of hard drives this is money spent on headroom you will not use. Its case is NVMe and longevity, not spinning disks. Drop it into a board with only PCIe 3.0 slots and it falls back to the 3.0 ceiling and loses half its reason to exist, so pair it with a PCIe 4.0 slot or buy the 9300 instead.
5. Adaptec AEC-82885T: a SAS expander to reach twenty-four bays
This one is not an HBA. An expander sits between an eight-port card and a large backplane and fans one card out to twenty-four or more drives, the way a network switch fans one uplink out to many hosts. Pair it with a 9300-8i and a single SFF-8643 link can feed a full 24-bay chassis with staggered spin-up. It runs around $55 to $65; check the live price.
The catch is shared bandwidth. Every drive behind the expander still funnels back through the host card’s PCIe 3.0 x8 ceiling, so this adds capacity, not throughput. For a wide archive pool of hard drives that is exactly the right tradeoff. For SSDs, add ports with a bigger card instead of stacking them behind an expander.
How to avoid buying the wrong card
Two mistakes account for most bad HBA purchases. The first is buying a RAID card instead of a host bus adapter. A card sold as a RAID controller hides each drive behind its own logic and presents a virtual volume, so ZFS never sees SMART data or per-disk errors, which is the whole reason you run ZFS. You want a plain HBA, and you want it in IT mode (initiator-target), not IR (integrated RAID). Many LSI cards ship in IR mode and are re-flashed; listings that say IT mode or P20/P24 IT have already done that work.
The second is provenance. The cheapest SAS3008 listings sometimes carry counterfeit or relabeled chips, and they show up as a card that drops drives under load or refuses to flash. Buy a card whose firmware revision the seller names, then confirm it after it arrives. On the SAS3 cards sas3flash -list prints the chip, firmware version, and mode; on SAS2 cards sas2flash -list does the same. If the output does not report IT mode, or the firmware string does not match the listing, return it before a single drive goes into the pool. If you are still choosing a pool layout to sit on top of the card, the ZFS RAID levels breakdown covers mirror versus RAIDZ and what each costs.
Match the cables to the card, not the drive
The connector trips more builds than the card itself. The 9300 and 9400 use SFF-8643 (internal Mini-SAS HD); the newer 9500 moved to SFF-8654 (SlimSAS); the 9211 uses the older SFF-8087 (Mini-SAS). Going from any of them to individual SATA or SAS drives needs a forward breakout cable that matches the card’s connector on one end: SFF-8643 to four SFF-8482 for SAS drives, or to four SATA, and the SlimSAS equivalent for the 9500. Connecting the card to a backplane instead needs a straight cable in the card’s own connector type. The reverse breakout cable looks identical to the forward one but wires the signals the wrong way and will not work, so buy forward breakout unless you are cabling a backplane. This one detail is behind a large share of “the card sees no drives” posts.
Cool the card or it will throttle
These are datacenter parts. They assume the forced airflow of a rackmount chassis, roughly 200 linear feet per minute over the heatsink, and they run hot without it. In a quiet tower with slow case fans a passively cooled SAS3008 will climb past its rated temperature during a resilver and either throttle or start dropping drives. The fix is cheap: a small fan clipped or zip-tied to the heatsink, or a slot fan aimed across the card. A surprising number of “the pool degrades under heavy write” reports trace back to a cooked HBA rather than a bad disk.
Do the bandwidth math before you overbuy
The card’s real ceiling is set by its PCIe slot, not its port count. A PCIe 3.0 x8 slot moves about 7.9GB/s; a PCIe 4.0 x8 slot about 15.8GB/s. Eight hard drives at 250MB/s each need roughly 2GB/s, well under either ceiling, so for a spinning pool every card here is overkill on bandwidth and the decision comes down to ports and provenance. The ceiling only bites with SSDs: eight SATA SSDs at 550MB/s each is about 4.4GB/s, still inside PCIe 3.0 x8, but sixteen of them, or a shelf of SAS SSDs, is where PCIe 4.0 and the 9500 stop being a luxury.
The five cards side by side
| Card | Controller | Ports | Link | PCIe | Slot ceiling | Best for |
|---|---|---|---|---|---|---|
| LSI 9211-8i | SAS2008 | 8 | 6Gb/s SAS2 | PCIe 2.0 x8 | ~4.0 GB/s | Budget pool of hard drives |
| LSI 9300-8i | SAS3008 | 8 | 12Gb/s SAS3 | PCIe 3.0 x8 | ~7.9 GB/s | The default TrueNAS build |
| Broadcom 9400-16i | SAS3416 | 16 | 12Gb/s tri-mode | PCIe 3.1 x8 | ~7.9 GB/s | 12 to 16 bays, no expander |
| Broadcom 9500-8i | SAS3808 | 8 | 12Gb/s tri-mode | PCIe 4.0 x8 | ~15.8 GB/s | NVMe and future pools |
| Adaptec AEC-82885T | expander | 24-wide | 12Gb/s | behind host | host-limited | Scaling one card to 24+ bays |
For most people the decision is short. Eight bays or fewer, buy the 9300-8i and a forward breakout cable. More than eight, add the AEC-82885T behind it or step up to the 9400-16i. Put NVMe in the pool and the 9500-8i is the one card that earns its price. Whichever you pick, match the cable, cool the card, and confirm IT mode before the first drive goes in, and the HBA becomes the part of the build you never think about again.
