Controller cards are installed on a motherboard to connect and control other PC components that include hard drives, disk drives, and input devices. Every component of hardware in your computer requires a controller for it to function.
Some add-on components require that you install a separate controller card for effective function. For example, there are several types of hard drives. Adding a hard drive that is different from the original drive on your computer will require a controller card. Unlike older PCs, modern computers have controller cards pre-installed on the motherboard as part of the chipset. Controller cards are designed to connect to a PC's motherboard through the peripheral component connect (PCI) slot.
The storage controller cards come in handy when adding storage, connecting to legacy storage devices, and replacing damaged storage ports. We have all new controller cards that connect through Thunderbolt and PCI Express to allow connection to internal and external storage options.
The SATA controller cards will help you address the need for more hard disk space by adding internal Serial ATA (SATA) and external SATA (eSATA) options to your computer. We have all types of SATA controller cards that interface through ExpressCard, PCI slots, PCIe, and Thunderbolt to get faster transfer speeds.
Choosing a RAID controller card specific to your needs should not be a difficult task. Keep in mind that the best RAID controller for a home server that uses inexpensive hard drives may not be best suited for SSD disks. Ensure that you fully understand the RAID setup and are aware of future needs when choosing a controller card. Most RAID controller cards have an upper limit of storage devices that can be supported.
The onboard RAID in a powerful CPU is sufficient for RAID 0 or 1 configuration. On the other hand, a RAID controller with a multicore processor and inbuilt cache memory is needed for RAID 50 or 60 setups. These high-end cards will increase write speeds and read speeds.
The SAS controller also referred to as an HBA (host bus adapter) is used in scenarios where you want to present disks to the server independently. It is the work of the operating system to identify the disks. A SAS controller has no RAID ability.
The SAS HBA controller cards are also used to support non-disk based devices such as tape drives, which is not possible with RAID controllers. Typically, a SAS HBA is all that you require if you are using modern storage software such as Windows Storage Spaces and ZFS. The SAS controller just like the RAID controllers are backward compatible with SATA disks. The ability to mix SATA and SAS on a single card is dependent on the type or model of card chosen.There are limitations to the use of SAS and RAID controllers dependent on the speed of PCIe lanes. SAS controllers will easily saturate PCIe 3.0x8 link (max out 7000MB/s) unlike mid-tier RAID cards that will stop at 700MB/s.