The Areca Controller Card
For a SATA controller card, this baby is huge. It measures the same length as an 8800GTS graphics card, and in weight it's almost the same, too. This is because of the layout and how much has to be packed onto the PCB. The card uses a PCI-E x8 interface using 1.1 specs.
Being a hardware based controller card, cache memory is used in order to increase the speed of the transfer rate, allowing the onboard processor to store the incoming and outgoing data. The module is a standard 256MB DDR2 SDRAM module running at 667MHz; you can install anything from 256MB up to 2GB to increase the cache size, which in turn will increase the overall system performance in RAID mode.
While the processor onboard handles the RAID 6 hardware engine, the actual RAID controller chips (one Marvell 88SX6041 and a 88SX6081 RAID chip), each handle six of the SATA ports and are dual-link combined to allow the 12 drives to be included into a single RAID array.
Rather than populating the PCB with 12 single SATA ports, MiniSAS ports are used that allow for four ports per single multi-channel port. This allows for more SATA ports by using MiniSAS to SATA cables; a much better (and cleaner) option overall.
One nifty feature is the ability to monitor the RAID arrays though a LAN. To that end, the controller has a built-in LAN port that connects to any standard Ethernet, allowing for monitoring and RAID array manipulation. You don't have to be at the PC in order to affect the RAID array, it's all done though a HTML process.