It is widely known that a disk drive is only as fast as its interface. This is especially true of the new solid-state devices, which may have jumped to light speed compared to their hard-disk brethren, but have so far been hampered by the same SATA II connections to the PC or server.
That state of affairs is improving rapidly, however, with the development of SATA III and PCIe 3.0 interfaces, although enterprises are now faced with the dilemma of which standard is the better facilitator of high-speed data connectivity.
From a hardware perspective, the choice is largely irelevent considering many of the latest controllers, like the Sandforce SF-1500 and SF-2000 lines, support the 6 Gbps rates of SATA III and are likely to adopt the 8 Gtps (gigatransfers per second) rate of PCIe 3.0 when that standard is finalized by the end of the year.
And it shouldn't be too difficult to find drives themselves that support one or both formats, considering the Sandforce controllers are proving to be hot commodities in storage OEM circles. OCZ, for example, will use them with the new Deneva line that supports both SATA and PCIe, as well as SAS and the company's own HSDL (High-Speed Data Link) format, which essentially marries a PCIe x 4 SATA interface with a SAS cable to deliver PCIe signals directly from drive to motherboard. Even Mac users will have multiple options with devices like Other World Computing's Mercury Extreme Pro drives, supporting the SF-2000 controller and PCIe x8 and x18 interfaces.
Of course, a growing number of PCIe-only drives are hitting ever-lower price points by doing away with SATA infrastructure altogether. A new company called Angelbird has an SSD board named Wings that features a PCIe x4 interface and an internal OS known as Virtue that is fully bootable on either Mac or PC. The board holds a Sandforce 1200, Intel NAND flash modules and a built-in USB port, providing yet another option for data transfer. List price for the 16 GB version is only $239.
So when you get right down to it, the question is not whether one approach or the other is supported by the coming hardware configurations. Rather, it boils down to the needs of each data environment. And it's here that things get a little murky because certain environments will most likely lend themselves to the more advanced capabilities of SATA, particularly now that it has a high-throughput option, while others may benefit from the more direct approach of PCIe. And still others may favor a combined approach.
One thing is clear, the days of simply swapping out short-stroked HDDs for solid state are over. Now that SSDs are carving their own niches in the data center, they will increasingly require customized support from their surroundings.