My Mac Pro 5.1 came with a cheap eBay PCIe SATA card which I've identified as a Silicon Image SIL-3132. The card looks slightly different from the producer's website though, more like this. I currently don't have any external SATA devices and Apple's system profiler says that no driver is installed even though I did install the software drivers for it. Perhaps the drivers don't load until a SATA device is connected? Anyway, I'm planning to buy an external SATA drive dock of some sort -preferrably something with 2 or more drive bays. I understand that for such a device with only one eSATA port I need a "multiplier" function (I suppose this is similar to daisy-chaining Firewire devices). Will this card work with a multiple bay device? The specs for the card say: The PB3132-2ESATA300 sup- ports port multipliers using FIS based switching. Traditional SATA controllers only support CMD based switching which can only access a single drive at a time, limiting performance to that of the drive being accessed. The PB3132- 2ESATA300 supports FIS based switching which accesses multiple drives simultaneously, effectively aggregating the bandwidth of the drives.