What is a controller card?
A controller card is an add-in PCI or PCI-Express card that enables IDE, SATA or SCSI devices to be connect to a computer. They often offer superior RAID performance for high performance hard drive arrays offering data redundancy and other complex features.
What do I look for in a controller card?
When buying a controller card it is worth checking it has all the features you want or may want in the future. There are several types of RAID and not all controller cards support them. Different models of controller card will offer different levels of performance. As a general rule PCI-Express cards are quicker than their PCI equivalents.
What is the difference between a software RAID card and a hardware RAID card?
A hardware RAID card is the more costly and almost always superior solution. By using a dedicated processor and memory they do not cause any significant overheads to the other components in the system, offer better performance and increased reliability. For mission critical workloads such as servers and photo/video editing workstations we would recommend a hardware raid card.
However for consumer use software RAID is a real option. It will improve reliability and with some versions of RAID the performance of your storage at a minimal cost. Software RAID cards work by “sharing” resources such as your CPU and RAM and the operating system with a driver taking over the work done by the on-board hardware in the hardware RAID card. While not offering the same levels of performance as a hardware RAID card it is often integrated onto motherboards and also on the lower cost controller cards making it the most common type of RAID solution.