The current PCIe add-in-card storage market is separated into two general architectures. The first is ground-up, native PCIe designs, such as the Micron P320h. These devices eschew a typical SATA/SAS controller in favor of specialized flash controllers that have native PCIe interfaces. This is where the market is heading. In fact, later this year, you should start to see many more devices that are NVMe-based. But, we will save that discussion for a later time. The second type of PCIe add-in-card storage takes more of a brute force approach. These devices typically have off-the-shelf SATA/SAS controllers and connect via a PCIe bridge. Think of a HBA/RAID card connected to a SATA SSD, but on a single card. These designs have many advantages and disadvantages. While the cost and time-to-market can be low, they are inherently limited due to the architecture."
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