The single-channel 2140S and dual-channel 2240S RAID controllers link Ultra320 SCSI devices to a PCI Express-based motherboard. The dual unit can handle up to 30 devices. Both support bootable arrays, hot-swap drives, and hot spares with automatic rebuild support. The single-channel, SCSI RAID 2140S costs $545. The dual-channel 2240S goes for $795.