Some links on this page are affiliate links: if you buy through them we may earn a commission, at no extra cost to you.
Short answer: A SATA SSD is the simplest way to add a boot drive without using a front bay; an IT-mode HBA is usually the best PCIe upgrade for a Gen8 running TrueNAS or ZFS; and a single-drive PCIe-to-M.2 NVMe adapter can work as secondary storage. Do not plan on native NVMe boot, and avoid multi-NVMe cards that need PCIe bifurcation unless the exact card has been proven on your server. The Gen8 has one expansion slot, so decide whether storage, networking or another add-in card matters most before buying.
Know the Gen8’s storage layout first
The MicroServer Gen8 is expandable, but it is not a modern NVMe-native server. Its main storage is built around four front-facing, non-hot-plug LFF SATA bays. Those bays connect through the backplane to the embedded HPE Dynamic Smart Array B120i controller. The system also has internal SATA connections, including a connection for the optical-drive (ODD) area, and one PCIe expansion position.
| Part | What it means for an upgrade |
|---|---|
| Four front bays | Use these for the main disk set. HPE identifies them as non-hot-plug; shut the server down before changing a drive. |
| ODD area and SATA connection | A practical place for a 2.5-inch SATA SSD, often used for the operating system or utility storage while leaving all four front bays free. |
| B120i | Embedded Smart Array storage controller with documented RAID 0, 1 and 10 options. It is not the same as an HBA presenting each disk directly. |
| PCIe slot | Can take an HBA, SATA controller, single-drive NVMe adapter, network card or another supported card—but there is only one slot to allocate. |
| Internal SATA links | HPE’s QuickSpecs describe five internal SATA connectors and a mix of 6-Gb/s and 3-Gb/s-compatible links. Do not assume every connector or bay has the same negotiated speed. |
HPE’s Gen8 QuickSpecs and User Guide are the authoritative starting points for layout and installation. The documentation describes PCIe and SATA storage, but does not document native NVMe storage or NVMe boot support. HPE also advises keeping unused bays and PCI openings properly filled or covered for cooling. On the front drive bays, older QuickSpecs identify bays 1 and 2 as 6-Gb/s and bays 3 and 4 as 3-Gb/s; verify the exact controller path and system configuration rather than assuming the ODD port’s speed.
Quick wins for a faster PC:
Fix the driver behind crashes, sound loss and screen glitchesFind Drivers →Clear out junk files and repair common Windows errorsFree Scan →Scan for outdated or missing drivers - takes under a minuteDriver Scan →Choose an upgrade by the job
| Your goal | Practical route | Main caveat |
|---|---|---|
| Boot without losing a front bay | 2.5-inch SATA SSD in the ODD area | Requires suitable mounting, data and power connections; boot order can take troubleshooting. |
| Keep installation simple | SATA SSD in a front bay | Uses one of the four storage bays. |
| TrueNAS or ZFS on the front disks | IT-mode HBA connected to the backplane | Uses the PCIe slot; cable, firmware, bracket and cooling all matter. |
| VM, application, cache or scratch storage | Single-drive PCIe-to-M.2 NVMe adapter | Treat NVMe as secondary storage; firmware boot is not assured. |
| A few more SATA devices | Well-supported PCIe SATA controller, or an HBA if direct disk access is required | Driver, controller mode and PCIe bandwidth limit the result. |
| Several NVMe drives | Usually choose a newer platform instead | Multi-drive cards may need bifurcation that the Gen8 is not documented to support. |
Adding a SATA SSD in the optical-drive area
This is often the best Gen8 upgrade when the priority is an operating-system drive rather than maximum benchmark performance. You need a 2.5-inch SATA SSD, a mount or bracket that fits the available ODD space, a SATA data cable to the motherboard’s ODD connection, and a suitable SATA power connection. The exact bracket and cable arrangement depends on the parts and chassis configuration; check clearance and power before closing the case. A 2.5-inch SATA drive in a front carrier is an even simpler alternative if using a bay is acceptable.
#1 Best Overall
- MODEL P86771-005: Ultra-compact HPE ProLiant MicroServer Gen11 featuring Intel Xeon 6325P 3.5GHz 4-core processor, ideal for SMB workloads and edge deployments
- FLEXIBLE MEMORY & STORAGE: Includes 32GB DDR5 UDIMM memory (expandable to 128GB) and 4 LFF-NHP drive bays. Features new MR408i-p controller support for enhanced storage performance
- READY TO RUN: Includes 1 x HPE 4TB SATA 6G Business Critical HDD, 180W external power adapter, and 1/1/1 year warranty for dependable plug-and-play server operation
- WHISPER-QUIET & SPACE-SAVING: Ultra-compact mini tower design fits easily in small office spaces; supports wall, flat, or vertical placement for deployment flexibility
- REMOTE MANAGEMENT READY: Includes HPE iLO6 with Silicon Root of Trust, TPM 2.0, and dedicated iLO-M.2 port kit for secure and efficient remote server administration
Do not assume the ODD connection runs at 6 Gb/s. HPE’s specifications describe multiple internal links and speed classes, but the exact ODD path is not established as a universal speed in the available documentation. If the path is limited to 3 Gb/s, the SSD’s sequential throughput will be capped below its SATA 6-Gb/s rating. That is usually a reasonable trade for booting, containers, light virtual machines and ordinary server services.
Boot behavior can be less straightforward than the physical installation. Community reports describe cases in which an ODD SSD is present but firmware starts another disk or reports a non-system disk, especially after controller-mode or boot-order changes. These are configuration-specific field reports, not a guaranteed flaw or an HPE-supported workaround. If the machine fails to boot after installation:
- Enter firmware setup with F9 and check that the intended controller mode and boot order remain selected.
- Confirm whether the OS bootloader was installed on the SSD you expect; another connected disk may contain a boot entry or boot sector.
- Check whether switching among AHCI, RAID or Legacy boot settings changed the path the firmware uses.
- Test with other disks disconnected only if doing so is safe for your data and configuration, then restore the original connections.
See the reported cases in the HPE Community boot-order discussion and this TrueNAS Gen8 boot discussion. They illustrate possible problems, not a universal resolution.
PCIe NVMe: useful as secondary storage, uncertain as a boot drive
A passive, single-drive PCIe-to-M.2 NVMe adapter is the least complicated way to try NVMe in the Gen8. It connects one NVMe drive to the PCIe slot without asking the motherboard to split the slot’s lanes. The operating system must include an NVMe driver, and you should verify physical fit, bracket height, clearance and cooling. An NVMe device may appear to the operating system after it loads even if the system firmware does not offer it as a normal boot target.
Rank #2
- MODEL P74439-005: Compact and affordable HPE ProLiant MicroServer Gen11 powered by Intel Pentium Gold G7400 3.7GHz processor, ideal for file sharing, NAS, and basic business workloads
- READY OUT OF THE BOX: Includes 16GB DDR5 UDIMM memory (expandable to 128GB), one 1TB SATA 6G Business Critical HDD, embedded Intel VROC SATA, dedicated iLO-M.2 port kit, 180w external power adapter and 1/1/1 warranty for dependable plug-and-play server operation
- WHISPER-QUIET & SPACE-SAVING: Ultra-compact mini tower design fits easily in small office spaces; supports wall, flat, or vertical placement for deployment flexibility
- INTEGRATED REMOTE MANAGEMENT: Comes with HPE iLO 6 and embedded TPM 2.0 for secure, license-free remote server administration through shared port access
- EXPANDABLE DESIGN: Two PCIe slots (including PCIe 5.0) and four LFF-NHP drive bays provide robust options for storage and component scalability. Features new MR408i-p controller support for enhanced storage performance
For that reason, use a SATA SSD for the operating system and treat PCIe NVMe as a possible secondary device for a VM datastore, application data or scratch work. Cache is workload-dependent: adding an SSD does not automatically make a NAS faster. A bootloader kept on SATA, USB or SD media may be used in custom arrangements, but it adds a dependency and maintenance burden; it is not equivalent to documented native NVMe boot. Do not buy on the assumption that a firmware update will add that feature.
Check the protocol, not just the connector shape. M.2 is a form factor: an M.2 SATA drive uses SATA signaling, while an M.2 NVMe drive uses PCIe. A passive NVMe adapter does not convert SATA to NVMe. Likewise, an M.2 notch or key alone does not prove that a drive and adapter speak the same protocol.
Be especially cautious with dual- or quad-M.2 carrier cards. Some require the motherboard to provide PCIe bifurcation (splitting lanes into separate device links); others include a PCIe switch. HPE’s Gen8 documentation does not confirm bifurcation support. A card that requires it is therefore a poor-risk purchase unless that exact card has been proven on the exact server and firmware. A newer PCIe generation printed on a card also does not guarantee higher speed here: the host link, lane allocation, firmware enumeration, card power and OS driver all affect operation.
Free tools Windows power users keep installed
One-click scans. No signup required.
Choosing an HBA for TrueNAS or ZFS
If the server will run TrueNAS or another ZFS-based system and the four front disks are the main storage pool, an HBA in IT mode is generally the better fit than putting the disks behind conventional hardware RAID. In IT mode, the HBA presents the individual disks to the operating system; ZFS can then manage the pool. By contrast, a RAID controller presents logical volumes. An HBA does not create a pool—the operating system does.
Rank #3
- MODEL P86811-005: HPE ProLiant MicroServer Gen11 preconfigured with Intel Xeon 6315P 2.80GHz 4-core processor, ideal for small business IT, edge workloads, and on-premise compute
- WHISPER-QUIET & SPACE-SAVING: Ultra-compact mini tower design fits easily in small office spaces; supports wall, flat, or vertical placement for deployment flexibility
- READY OUT OF THE BOX: Includes 16GB DDR5 UDIMM memory (expandable to 128GB), dedicated iLO-M.2 port kit, embedded Intel VROC SATA controller for Gen11 servers, 180w external power adapter and 1/1/1 year warranty for dependable plug-and-play server operation
- EXPANDABLE DESIGN: Two PCIe slots (including PCIe 5.0) and four LFF-NHP drive bays provide robust options for storage and component scalability. Features new MR408i-p controller support for enhanced storage performance
- INTEGRATED REMOTE MANAGEMENT: Comes with HPE iLO 6 and embedded TPM 2.0, enabling secure, remote administration through browser, command line, or API with shared port access
Commonly considered cards include LSI/Broadcom SAS2008-based models such as the 9211-8i and SAS2308-based models such as the 9207-8i. HPE-branded options such as the P222 are also discussed in Gen8 storage setups. None is a universal plug-and-play recommendation: compatibility depends on the precise card, firmware, operating system, physical fit and cable. A card advertised as “IT mode” may have unofficial firmware or questionable provenance, so verify its identity and mode before trusting it with disks.
Pay attention to the connection at both ends. SAS HBA connectors are not ordinary SATA ports. SFF-8087 and SFF-8643 are different connector generations and are not interchangeable. Identify the HBA connector and backplane connection, then buy the correct cable—often a forward breakout cable for connecting an HBA to individual SATA devices. Check whether the card needs a low-profile bracket and whether it can be adequately cooled in the compact chassis. Used and rebranded cards vary in firmware, authenticity, condition and included cables; buy from a seller with a return option.
The trade-off is the Gen8’s single PCIe slot: an HBA occupies it, so that same slot cannot also take a 10GbE card, a SATA controller or an NVMe adapter. Decide which resource matters more before ordering parts. A community example of a Gen8 using an HPE P222 for front-bay disks and separate onboard SATA connections for SSDs is useful as an illustration, not a guarantee of compatibility: TrueNAS hardware discussion.
Adding SATA ports with a PCIe controller
A SATA expansion card can add connections for SSDs or other SATA devices when the built-in connectors are already in use. Favor a controller with documented driver support for your intended operating system, a suitable low-profile bracket, and a non-RAID or direct-disk mode if the OS needs individual disk visibility. Check whether it uses a port multiplier; for serious storage, avoid relying on one unless you have verified the controller, OS and workload.
Rank #4
- HP ProLiant MicroServer Gen10 Plus is the perfect entry-level tower server for home office or small business; made for easy deployment, management, and small business server roles
- Get powerful performance with the Intel Xeon E-2224 Quad-Core 3.4GHz 8MB CPU with up to 4.6GHz Turbo
- Speed, quality and reliability with 16GB DDR4 unbuffered memory; store plenty of data with 4TB SATA hard drives
- Keep your data safe with software RAID
- Hard drives and memory upgrades included separately NOT installed, installation required.
More ports do not mean unlimited throughput. All devices on a card share its PCIe connection and controller resources, and the Gen8’s PCIe generation and lane allocation limit aggregate bandwidth. Driver support is also OS-specific: a card that works in one version of Windows may not work in the Linux or BSD base used by a NAS operating system. If a card is detected but its drives are not, check the chipset’s driver support, firmware mode, port-multiplier behavior and cabling before blaming the disks.
Install safely and verify before creating a pool
Follow the HPE User Guide for chassis access and component installation. At a minimum:
- Shut down the server and disconnect AC power before opening it.
- Install the drive or PCIe card, secure it with the correct bracket and connect the required data and power cables.
- Route cables clear of fans and moving parts. Keep the intended airflow path open and fit blanks in unused bays or PCI openings as appropriate.
- Reinstall the cover, reconnect power and enter setup with F9 if you need to check controller settings or boot order.
- Boot the operating system and confirm the device is present before creating a RAID set, filesystem or pool.
On Linux, these commands help identify hardware and disks. They are OS-level diagnostics, not HPE-specific utilities:
lspci -nn
lspci -nn | grep -Ei 'sata|sas|raid|nvme|storage'
lsblk -o NAME,MODEL,SERIAL,SIZE,TYPE,FSTYPE,MOUNTPOINTS
nvme list
sudo smartctl --scan
dmesg | grep -Ei 'nvme|ahci|ata|sas|scsi'
zpool statusnvme list requires the NVMe command-line utility; smartctl commands require smartmontools, and zpool status applies only to a ZFS system. To inspect a particular SATA/SAS drive, use sudo smartctl -a /dev/sdX after identifying the actual device. Never copy an example device name into a destructive command: confirm model and serial number before formatting, wiping, adding a disk to a pool or flashing firmware.
Troubleshooting by symptom
- NVMe shows up in Linux but will not boot: The OS may have an NVMe driver even though Gen8 firmware does not expose the drive as a boot target. Boot from SATA and use NVMe as secondary storage, or choose a SATA OS drive rather than relying on a custom bootloader.
- ODD SSD is detected but the server reports a non-system disk: Check boot order, controller mode and which disk actually contains the bootloader. Multiple connected disks can complicate firmware selection; reported fixes vary by configuration.
- SATA card works in one OS but not the NAS OS: Verify chipset and driver support in that OS, controller mode, card firmware and whether the card depends on a port multiplier.
- HBA appears but disks do not: Check the exact cable type and direction, backplane power, HBA firmware mode and controller initialization. A connector that fits is not proof that the cable is the correct one.
- System becomes unstable after adding an HBA: Check seating, bracket interference, firmware mismatch, card condition and card temperature. Compact chassis airflow can be inadequate for a hot adapter.
- A multi-M.2 card shows only one drive: It may require bifurcation, rely on an incompatible PCIe switch, or have a slot that supports SATA rather than NVMe. Check the card’s exact design and requirements.
- SSD is slower than expected: Check whether it is on a 3-Gb/s SATA link, whether a PCIe device negotiated a narrower or older link, whether multiple devices share a controller, and whether the SSD is throttling from heat.
Before buying an adapter or controller
- Confirm the exact protocol: SATA or NVMe; M.2 alone is not enough.
- Check whether the card needs PCIe bifurcation or includes its own PCIe switch.
- Confirm operating-system driver support and the intended mode (IT/HBA/JBOD versus hardware RAID).
- Match the cable connector and direction to the HBA and backplane; do not confuse SFF-8087 with SFF-8643.
- Verify bracket height, card length, chassis clearance, power connections and cooling.
- Account for the one-slot trade-off among storage, networking and other expansion.
- For used hardware, verify model, firmware, included cable and return terms rather than relying on a broad “Gen8 compatible” claim.
If the requirement is several NVMe drives, guaranteed NVMe boot, high-speed networking and more storage bandwidth at once, compare the total cost and effort of adapters with moving to a newer server or workstation. The Gen8 remains useful when its limits are part of the plan, not something a stack of add-ons is expected to erase.
Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
