IBM has been developing the FlashCore modules that sit at the heart of the IBM FlashSystem portfolio for some time now. The new third-generation FlashCore is used in the FlashSystem 5200, FlashSystem 7300 and FlashSystem 9500 arrays.
IBM FlashCore is not an ordinary SSD. It does not simply serve data over an NVMe interface. IBM FlashCore is a sophisticated computational storage device. The logic inside the module allows QLC flash to deliver better, more reliable performance at a higher density than most TLC-based solutions.
FlashCore lets you build a device with twice the endurance of a standard NVMe flash drive. The latest generation of IBM FlashCore is available in effective capacities ranging from 22TB to 116TB — all in a 2.5-inch dual-port U.2 NVMe form factor.
What is inside the module?
FlashCore is a computational storage device that combines NAND flash, DRAM and MRAM for caching with a substantial amount of compute to deliver more functionality than a conventional SSD. It also takes some computational work, such as compression, off the storage array and performs it on the drive itself. The result is a highly efficient and flexible architecture.
The compute side of the storage consists of ARM processor cores embedded within flexible, reprogrammable logic arrays. The primary purpose of this logic is to manage the module's QLC flash memory. On one hand, QLC media is somewhat slower and less durable than the TLC flash commonly used in storage systems. On the other, it has its advantages: this memory is cheaper and denser. So once the shortcomings of such drives are overcome, it becomes possible to build high-density, energy-efficient arrays based on them.
IBM has managed to deliver a QLC-based flash drive that is as reliable as any TLC-based solution on the market — and in many cases higher-performing. A great deal of low-level technology goes into this, but the essence of the work is managing the health of the NAND at block level. All of it is programmed into each FlashCore module in a way that increases reliability.
It is also worth noting that FlashCore focuses on compression as one of the most important characteristics of any enterprise storage array. This has a positive effect on both the efficiency and the cost of the storage system. The purpose of compression is to offload and accelerate storage workloads wherever that makes sense.