Preface

Solid State Drives (SSDs) are gaining momentum in enterprise and client applications, replacing Hard Disk Drives (HDDs) by offering higher performance and lower power. In the enterprise, developers of data center server and storage systems have seen CPU performance growing exponentially for the past two decades, while HDD performance has improved linearly for the same period. Additionally, multi-core CPU designs and virtualization have increased randomness of storage I/Os. These trends have shifted performance bottlenecks to enterprise storage systems. Business critical applications such as online transaction processing, financial data processing and database mining are increasingly limited by storage performance. In client applications, small mobile platforms are leaving little room for batteries while demanding long life out of them. Therefore, reducing both idle and active power consumption has become critical. Additionally, client storage systems are in need of significant performance improvement as well as supporting small robust form factors. Ultimately, client systems are optimizing for best performance/power ratio as well as performance/cost ratio. SSDs promise to address both enterprise and client storage requirements by drastically improving performance while at the same time reducing power. Inside Solid State Drives walks the reader through all the main topics related to SSDs. Chapter 1 provides an overview of the SSD market and applications, including a review of client PC, tablet, and enterprise computing usage models. A Solid State Drive is a very complex system: Chap. 2 contains an overview of the main blocks, including hardware and software. Chapters 2 and 3 cover different SSD implementations with host interfaces ranging from SAS/SATA to PCI Express (PCIe). SAS/SATA offer compatibility with legacy storage infrastructure. However, for many applications, NAND Flash read and write speeds are exceeding the capabilities of these legacy interconnects. PCIe SSDs overcome this bottleneck and deliver unparalleled performance while, at the same time, reducing latency, power and cost by eliminating the traditional storage infrastructure and attaching directly to a platform’s PCIe I/O interconnect. SSDs and HDDs can also be combined together in various forms, as explained in Chap. 4 where “hybrid” storage is analyzed.