Expansion cards and controllers add storage, network or interface capabilities to a mainboard through its slots. This category suits server and workstation owners, IT resellers and NAS users. It covers RAID and storage controllers, network adapters and add-in interface cards from HP Enterprise, Dell, Fujitsu and Cisco, among others.
How to choose an expansion card or controller
Card function. Decide first what the card must do: manage disks (RAID controller or host bus adapter), add network ports, add extra M.2 SSD slots, or provide legacy interfaces such as serial ports. A RAID controller combines drives into arrays with redundancy, while a host bus adapter simply passes drives through to the operating system, which suits software-defined storage.
Slot and interface. Check which PCI Express slots are free on your mainboard, how many lanes they provide (x1, x4, x8 or x16) and whether the card is full height or low profile. A card will usually work in a longer slot than it needs, but a shorter slot or a slot wired with fewer lanes can limit speed. Also check the physical space in the case, since some cards are long or need extra airflow.
Ports and speed. For network adapters, match the port speed and connector type to your switch and cabling, for example copper RJ45 or SFP+ fibre. For storage controllers, check how many drives it can connect and whether it takes SAS, SATA or both. Buying more ports than your switch or drive bays can use adds cost with no benefit.
Server and software compatibility. Cards sold under HP Enterprise, Dell or Fujitsu names are often designed for that maker's own servers, and they may rely on specific firmware or drivers. Compare the part number with your server's compatibility list and confirm that drivers exist for your operating system or hypervisor before ordering.
Brands we carry
- HP Enterprise: known for ProLiant servers, with storage controllers and network adapters made to fit that server family.
- Dell: maker of PowerEdge servers, whose PERC RAID controllers are a common sight in Dell-based storage setups.
- Fujitsu: supplies PRIMERGY server hardware, including RAID controllers matched to those systems.
- Cisco: a networking specialist, so its cards in this category centre on network connectivity for server environments.
- QNAP: a NAS manufacturer, known for expansion cards that add network speed or M.2 SSD capacity to its storage devices.
- EXSYS: focuses on industrial computing, including add-in cards for serial, USB and other interfaces.
Also in our range: Gigabyte.
Frequently asked questions
What is an expansion card used for?
An expansion card adds a function that the mainboard does not offer or does not offer in sufficient quantity. Typical examples are extra network ports, a RAID controller for disk arrays, additional SATA or SAS connections and M.2 SSD adapters. It is fitted into a free slot, usually PCI Express.
What is the difference between a RAID controller and a host bus adapter?
A RAID controller manages the drives itself and presents them to the system as one or more arrays with redundancy or extra speed. A host bus adapter passes each drive straight to the operating system without building arrays in hardware. Choose a RAID controller for traditional hardware RAID, and an adapter for software-defined storage that manages the disks itself.
Will an expansion card fit any mainboard?
No, the card must match an available slot type and have enough physical room. Most modern cards use PCI Express, and a card will normally run in a slot with the same or a larger lane count. Server-branded cards can also require specific firmware, so check the compatibility list for your system.
Do I need drivers for a network or controller card?
Usually yes, although many operating systems include basic drivers for common chipsets. Server controllers and faster network adapters often need the manufacturer's driver and firmware for full performance and management features. Check that your operating system or hypervisor is supported before you buy.
