Explore the basic storage form factors available for IBM Power Systems -- Flash, SSD, and HDD products.
IBM flash-optimized products
IBM FlashSystem™ and PCIe Flash Adapters are low latency devices based on an optimized and integrated controller design using NAND flash memory as the storage media. IBM FlashSystem family are high capacity, all-flash appliances that can be attached through Fibre Channel connection to Power servers and can also be integrated into shared Power SAN environments. PCIe Flash Adapters are high performance, lower price, and lower capacity solutions that are installed inside Power servers creating a nearly direct connection from the processor to flash. This enables the lowest possible latency for flash access. PCIe Flash Adapters provide very high IOPS with relatively low investment and require no additional rack space.
Solid-state drives (SSD)
SSD are popular high perfromance flash memory devices. SSD are a standard disk drive form factor with SAS connectors that contain flash memory. SSD provide significantly higher I/O operations per second (IOPS) than HDD. SSD can deliver high performance and high capacity utilization. SSD are an attractive alternative to HDD and can significantly reduce acquisition and operating costs for applications gated by I/O performance.
The combination of HDD and SSD allow each type of storage to perform at its best; the HDD can be focused on “cold” data that is not often accessed, while the high performance capability of SSD is focused on the “hot”, frequently accessed data. The high performance capabilities of SSD and the cost effectiveness of HDD can complement each other in a hybrid configuration that achieves the most effective level of price/performance.
Hard disk drive (HDD)
HDD stores and transfers data using spinning disks and moving armature. HDD are low cost/high capacity storage devices with relatively modest I/O performance (time required to read and write data). HDD are acceptable for applications that require large storage capacity and applications that are relatively insensitive to I/O performance. Many of today’s most important applications such as OLTP and real-time databases require better I/O performance than HDD can deliver. In these situations, HDD limits application performance and leaves other expensive system resources underutilized. Increasing overall server utilization with Flash/SSD can result in significant savings in hardware costs, licensing costs, floor space, and energy consumption.
Of these three alternatives, flash optimized solutions, such as IBM FlashSystem and IBM Flash Adapters offer the highest performance (measured in terms of latency, peak IOPS and bandwidth). SSD also offer excellent IO performance in a flexible package that can be connected to Power Systems in a variety of ways. SSD are the building bocks for high performance SSD drawers and can also be plugged directly into Power servers. SSD are also found in hybrid SAN arrays (arrays that offer combinations of SSD and HDD in a single solution). HDD offers the lowest cost per GB capacity but have high latency and low IOPS. When used in hybrid arrays, they are almost always used in conjunction with software, such as IBM Easy Tier, which automatically migrates frequently accessed data to the SSD and less frequently accessed data to HDD.