Question 1

Can I use an HPE SmartArray controller in a non-HPE server?

Accepted Answer

Technically it will often initialise, but you'll lose most of the management functionality — HPE SmartArray controllers are designed to integrate with HPE's iLO management interface, and outside that ecosystem, monitoring, alerting, and firmware updates become unreliable or unavailable. For non-HPE servers, vendor-agnostic controllers from Broadcom (MegaRAID) or Intel (VROC) are the correct choice. The cost saving of buying a surplus HPE card rarely outweighs the operational headache.

Question 2

What's the difference between a RAID controller and a simple SATA expansion card?

Accepted Answer

A RAID controller has a dedicated onboard processor and cache memory to manage RAID calculations in hardware, independently of the host CPU. A SATA expansion card simply adds ports — any RAID functionality relies entirely on the host CPU (software RAID), which adds overhead and is significantly less reliable for production use. For anything beyond a home lab or workstation, hardware RAID controllers are the correct solution. The performance and data integrity difference is substantial under load.

Question 3

Is RAID 5 still safe to use in 2026?

Accepted Answer

RAID 5 remains viable for drives under 4TB, but becomes increasingly risky with larger drives due to the extended rebuild window — during which a second drive failure would cause total data loss. With modern high-capacity HDDs (8TB+), a RAID 5 rebuild can take 24–48 hours, creating an unacceptably long vulnerability window. RAID 6 or RAID 10 are the recommended alternatives for new deployments. If your controller supports RAID 60, that's the preferred choice for large arrays with six or more drives.

Question 4

Do I need battery-backed cache on my RAID controller?

Accepted Answer

Yes, for any write-intensive or production workload. Without battery-backed cache (BBU) or flash-backed write cache (FBWC), a power interruption during a write operation can corrupt your RAID array — even if the drives themselves are fine. Controllers without BBU typically disable write caching by default, which significantly reduces write performance. If your budget only stretches to a controller without BBU, ensure your server has a UPS as a minimum safeguard.

Question 5

What does '8i' or '16i' mean in a RAID controller model name?

Accepted Answer

The number indicates the port count and 'i' denotes internal connectors. An 8i controller supports up to 8 drives via internal SAS/SATA cables; a 16i supports up to 16. Some controllers also carry an 'e' suffix (for example, 32i/e), indicating external SAS ports for connecting JBOD expansion shelves. Always match the port count to your current drive count plus anticipated growth — upgrading a controller later means a full array migration.

Question 6

Are cheap RAID controllers worth buying for a home server or NAS?

Accepted Answer

For a home lab or non-critical NAS, budget controllers from Dawicontrol or StarTech (available from 60 £) are perfectly adequate — particularly for RAID 1 mirroring or simple JBOD configurations. The risk comes if you use them for RAID 5/6 on important data: budget controllers often lack battery-backed cache and may have slower rebuild times, increasing exposure during drive failure. For anything holding irreplaceable data, spend more or use software RAID with a proper backup strategy instead.

Question 7

What RAID controller accessories do I actually need?

Accepted Answer

At minimum: SAS/SATA cables (often not included), and a battery backup unit (BBU) or flash-backed write cache module if not bundled with the controller. For HPE SmartArray controllers, the Energy Pack or FBWC kit is sold separately and is essential for safe write caching. A low-profile bracket may also be required for 1U server installations. Check the full accessory list before purchasing — the controller price rarely tells the whole story.

RAID Controllers Price Comparison

RAID Controllers price comparison UK