A hardware RAID makes use of a dedicated physical controller that stores information about hard disks and manages both how the data is written and how the volume is accessed. Therefore, hard disks are connected to a RAID controller card which is inserted into the PCI-Express (PCI-e) slot on the motherboard. This is implemented similarly both in large servers and desktop computers. However, in external devices RAID controllers are built-in. A software RAID includes a commonplace disk controller, while all drives within the array are managed by special software. This could be a much cheaper way to build a RAID data storage system, but it can also be considerably slower since it adds more workload on the CPU and RAM.