RAID Controllers
RAID Controllers covers the cards that build arrays out of server disks: HPE MegaRAID MR216i and MR416i controllers, Smart Array P408i-a, LSI MegaRAID 9361-series cards, Dell PERC controllers and their cache batteries. The newer MR416i-class controllers are tri-mode and run SAS, SATA and NVMe drives from one card. Older listings include controllers from IBM, NetApp and earlier HP generations, which still matter when you're keeping an installed array alive.
RAID Controllers: 1,707 products
Buying guide
Choosing a RAID controller
Cache and its backup
A controller with write-back cache needs a battery or capacitor so cached writes survive a power cut. Without it, many controllers fall back to write-through, which is slower.
Tri-mode cards
Tri-mode controllers drive SAS, SATA and NVMe from the same ports, but only behind a backplane wired for it. They don't turn an older SAS backplane into NVMe.
Keep arrays in the family
RAID metadata is vendor-specific. An array built on a MegaRAID controller imports on another MegaRAID, and a Smart Array array on another Smart Array — not across vendors.
RAID Controllers
Frequently asked questions
Can I move a RAID array to a new controller?
Within the same controller family, usually yes: the new controller reads the array's metadata from the drives. Moving between families, such as from Smart Array to MegaRAID, generally means rebuilding the array and restoring data.
What is a RAID controller battery for?
It protects data sitting in the controller's write cache. If power fails, the battery keeps the cache alive, or flushes it to flash, until power returns and the writes can complete.
What's the difference between a RAID controller and an HBA?
A RAID controller combines drives into arrays and presents them as volumes. An HBA passes each drive straight to the operating system, which is what software RAID, ZFS and vSAN prefer.
