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StashRaid

Storage Parameters

Usable Capacity

12 TB

Fault Tolerance

4

Array Resilience

Architecture

RAID 5 • Parity

Fault Tolerance

1 Concurrent Failures Allowed

Current Configuration

RAID 5 (Parity)

12 TB Usable

Total RAW: 16 TB

Disk 01DATA
Disk 02DATA
Disk 03DATA
Disk 04PARITY

Total Drives

4 x 4 TB

Efficiency

75% Utilized

Usable: 12 TBWasted to redundancy: 4 TB

Pros & Cons

  • PRO: Good balance of capacity/speed/safety

  • PRO: Cost-effective redundancy

  • CON: Slower writes due to parity calculation

    This setup prioritizes redundancy but has associated performance or capacity costs.

Storage Hardware Guide

HBA vs. RAID Controller Guide

If you are building a ZFS, Unraid, TrueNAS, or any software-defined storage server, choosing between a Host Bus Adapter (HBA) and a hardware RAID controller is one of the most consequential decisions you will make. Get it wrong and you lose data integrity, performance, or both. This guide explains the difference, walks through the best HBAs to buy, and shows you how to cross-flash a RAID controller into IT mode.

HBA vs. RAID Controller — What is the Difference?

At the physical level an HBA and a RAID controller look almost identical: a PCIe card with SAS/SATA ports. But what they do with the drives attached to them is fundamentally different.

IT Mode (HBA / Initiator Target)

  • Passes drives through directly to the OS — no abstraction layer
  • The OS sees raw disk devices (sdX, daX) and manages RAID/ZFS/pooling itself
  • Full SMART passthrough, TRIM/discard support, and native error reporting
  • Required for ZFS, Unraid, TrueNAS, Ceph, and mdadm
  • Lower latency — no extra processing hop through the RAID chip

IR Mode (RAID Controller / Integrated RAID)

  • Presents a virtual disk to the OS — the controller hides the physical drives
  • The OS sees one block device (e.g., /dev/sda) regardless of how many drives are in the array
  • Requires vendor-specific management tools (MegaRAID, StorCLI) to check drive health
  • Often blocks SMART, TRIM, and native command queue passthrough
  • Can cause silent data corruption when paired with ZFS (double parity, write hole issues)

Why ZFS and Unraid require IT mode

ZFS manages data at the block level — it needs direct access to every physical drive to verify checksums, detect bit rot, and self-heal. A RAID controller in IR mode intercepts reads/writes and presents a virtual block device, so ZFS cannot see individual drives. This defeats ZFS's integrity guarantees. Unraid similarly needs direct drive access for its parity scheme. Always run these operating systems with an HBA in IT mode.

Best HBA Comparison Table

The table below covers the most common and recommended HBAs for home lab and small-to-medium enterprise storage builds. All prices listed are approximate used market (eBay).

ModelPortsSpeedConnectorPrice (Used)Best For
LSI 9207-8i8 (2×4)6 Gb/s SAS 2.0SFF-8087$30–50Budget builds, SATA SSD pools
LSI 9300-8i8 (2×4)12 Gb/s SAS 3.0SFF-8643$50–90Best value, 12 Gb/s SAS HDDs
LSI 9400-16i16 (4×4)12 Gb/s SAS 3.0SFF-8643$150–250High-density JBOD builds
Broadcom 9500-8i8 (2×4)24 Gb/s SAS 4.0 / PCIe 4.0SFF-8654$350–500NVMe + SAS, future-proof
Broadcom 9500-16i16 (4×4)24 Gb/s SAS 4.0 / PCIe 4.0SFF-8654$500–700Enterprise NVMe + SAS clusters

* SAS 4.0 (24 Gb/s) controllers also support NVMe via Tri-Mode. Prices reflect eBay sold listings as of mid-2025.

Where to Buy — and Knockoff Warnings

eBay (Used)

Best prices — $30–90 for 9207/9300 series. Look for sellers with 98%+ positive feedback and "pulled from working server" listing text.

Browse eBay listings

B&H Photo

New stock, reliable returns, genuine Broadcom/LSI product. Typically 20–30% more expensive than eBay but includes warranty.

Shop B&H

Amazon

Convenient but the highest risk of counterfeit/fake LSI cards. Avoid third-party sellers with no reviews. Prefer "sold by Amazon" or Broadcom direct.

Check Amazon

Fake & Knockoff Warning

Counterfeit LSI and Broadcom cards are rampant on Amazon and AliExpress. Telltale signs: missing or crooked branding, cheap PCB, no heat sink, or suspiciously low price (e.g., $15 for a 9300-8i). Fake cards often use salvaged chips or fail under sustained load. Stick to reputable eBay resellers (e.g., TheArtOfServer) or B&H for peace of mind.

Cross-Flashing a RAID Controller to IT Mode

If you already own a RAID controller (or find a good deal on one), you can cross-flash it to IT mode firmware. The exact steps vary by chipset family, but the general process is:

1

Boot into DOS or UEFI Shell

Create a bootable USB with FreeDOS or load the UEFI Shell from your motherboard. You will run the SAS flash utility (sas2flash or sas3flash) from this environment.
2

Identify Your Controller

Run sas2flash -list to confirm the controller model and current firmware version. Record the SAS address — you will need it later.
3

Download IT Mode Firmware

Obtain the correct IT-mode firmware for your chipset from Broadcom's support site or community mirrors. For LSI 9207-8i use P20 firmware; for 9300-8i use P16. Verify file integrity with SHA-256 checksums when available.
4

Erase Existing Firmware

sas2flash -o -e 6 — this erases the controller's existing firmware and BIOS. The card will appear unresponsive until you flash new firmware. Do not reboot at this step.
5

Flash IT Mode Firmware

sas2flash -o -f 9207-8i_IT.bin -b mptsas2.rom— flash the firmware binary and the BIOS ROM (if you want boot support). For UEFI systems, add the UEFI BSD ROM file as well.
6

Verify and Reboot

Run sas2flash -list again to confirm the firmware version changed to P20 (IT). Power off, disconnect power, re-seat the card, then boot your OS. Your drives should now appear individually.
7

Install OS Drivers

Modern Linux kernels include the mpt3sasdriver. Verify with lspci -k | grep -A 3 LSIand confirm your drives show up under lsblk or in your storage web UI.

⚠️ Cross-flashing voids warranties and carries a small risk of bricking the card. Always use a known-good firmware file for your exact model and revision. See the community ServetheHome flashing guide for detailed model-specific instructions.

SAS vs. SATA on the Same HBA & Cabling

SAS and SATA Compatibility

All SAS HBAs and backplanes support both SAS and SATA drives on the same port. SATA drives use the same physical connector (SFF-8482 for SAS). The controller auto-negotiates the protocol per drive. You can mix SAS HDDs, SATA SSDs, and SATA HDDs on one cable — though mixing SAS and SATA on the same SAS expander chain can cause issues with some older expander firmware.

SFF-8087 vs SFF-8643 vs SFF-8654

SFF-8087 (Mini SAS, 4-lane): Used by SAS 2.0 (6 Gb/s) controllers like the 9207-8i. Common in older server backplanes.
SFF-8643 (Mini SAS HD, 4-lane): Used by SAS 3.0 (12 Gb/s) controllers like the 9300-8i and 9400-16i. Physically smaller, not compatible with 8087 without an adapter.
SFF-8654 (SlimSAS, 4/8-lane): Used by SAS 4.0 (24 Gb/s) and PCIe 4.0 controllers like the Broadcom 9500 series. Supports NVMe via Tri-Mode.

Cable Adapters and Breakout Cables

To connect HBA ports to individual drives, use breakout cables: one SFF-8087/8643 to four SATA connectors. For backplane connections, use standard SFF-8087 to SFF-8087 or SFF-8643 to SFF-8643. Forward/reverse breakout variants exist — pay attention to which side the breakouts are on (HBA side vs drive side). Adapter cables like SFF-8643 to SFF-8087 let you use a newer 9300 HBA with an older backplane.

Related StashRaid Guides

ZFS vs. Hardware RAID

Understand why ZFS needs direct disk access and why hardware RAID can corrupt your data.

Build Planner

Calculate drive pools, parity requirements, and chassis needs for your storage server.

Gear Recommender

Get personalized hardware recommendations based on your budget and use case.

Frequently Asked Questions

Can I use an HBA in IT mode with a hardware RAID enclosure (like a Dell MD1200)?

Yes. When the enclosure is a JBOD (just a bunch of disks) with a SAS expander, an HBA in IT mode communicates with each drive individually through the expander. The enclosure adds latency but works fine. Avoid enclosures that perform hardware RAID internally.

Do I need an HBA if my motherboard has enough SATA ports?

For 6 drives or fewer, onboard SATA ports work fine with ZFS. Beyond that, onboard SATA controllers often share limited PCIe lanes, can drop connections under load, and lack JBOD management features. An HBA offloads the controller and adds expandability via SAS expanders.

What is the difference between a 9207-8i and a 9300-8i?

The 9207-8i uses SAS 2.0 (6 Gb/s per lane, PCIe 3.0 x8) and SFF-8087 connectors. The 9300-8i uses SAS 3.0 (12 Gb/s per lane, PCIe 3.0 x8) and SFF-8643 connectors. For spinning HDDs you will not notice a difference — HDDs top out at ~280 MB/s. For SATA SSDs the 9300 helps. For NVMe you need the Broadcom 9500 series.

Can I flash a RAID controller to IT mode without a DOS/UEFI boot?

Yes — some models support flashing from Linux using sas3flash or sas2flash utilities running in single-user mode. The card must be the only storage controller in the system during the flash. UEFI shell is generally safer and more reliable.

Will an HBA work in a PCIe x4 or x1 slot?

Physically yes (most HBAs are x8). Electrically, an x4 slot bottlenecks 1–2 SAS SSDs. For spinning HDDs and low-density builds it works fine. Avoid x1 slots — the mechanical mod to fit an x8 card in an x1 slot is unreliable and risks shorting pins.

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