There is growing enterprise adoption of flash memory in its various flavors – solid-stated drives (SSDs), all-flash and hybrid storage arrays, server storage (PCIe) and server memory – but as with any industry, there are winners and losers. At the same time SSD pioneer OCZ has received court approval to be acquired by Toshiba, flash storage vendor SANdisk has announced it is shipping the ULLtraDIMM SSD line, based on the flash-based Memory Channel Storage offering from Diablo Technologies, as well as its first OEM customer, IBM.
Last week Toshiba, a manufacturer of flash memory, agreed to acquire all of OCZ’s enterprise and consumer SSD business, as well as the OCZ brand, for $35 million. This week SanDisk officially confirmed that its Diablo-based ULLtraDIMM drives will be used by IBM under the eXFlash DIMM brand name, initially as options for its System x3850 and x3950 X6 servers, providing up to 12.8TB of flash capacity.
Storage guru George Crump, Storage Switzerland, has been covering the move to memory channel storage for the last six months and calls it the next logical upgrade from drive-attached and PCIe-attached flash storage. “By putting the flash directly on the memory bus traditional storage latency is almost completely eliminated.”
Writing about IBM’s new servers, he noted that customers install server side flash solutions specifically to address performance problems, and for most environments every additional ‘ounce’ of that performance can generate an additional ‘pound’ of revenue. “Memory channel storage is clearly the next frontier in server side flash acceleration. Its 3X reduction in latency can produce many more ounces of performance and its density allows that performance to be achieved at a more cost effective price.”
The most important aspect of the IBM announcement is that the new generation of EXA (also known as X6) enables x86-based servers to access up to 12 TB of storage cache that can be deployed on Flash DIMMs (dual in-line memory modules) that are attached to the processor via the memory bus, said Joe Clabby, Clabby Analytics. “As a result this innovation, I now feel very comfortable recommending IBM’s System x solutions with X6 architecture to enterprises looking to run large-scale ERP (enterprise resource planning), large database business analytics, large database serving, and high-IOPs virtualization workloads.”
Analyst Charles King, Pund-IT, believes IBM’s eXFlash memory-channel storage should enable customers to capture the maximum value offered by innovative new flash technologies to enhance cloud, analytics and other virtualization-dependent workloads. “In essence, IBM’s new X6 platform has the I/O performance and memory scalability necessary to support and virtualize large, intensive business applications, including the most mission critical workloads.”
Forrester analyst Richard Fichera called eXFlash a performance game-changer. “The MCS architecture, and IBM’s eXFlash offering in particular, allows flash memory to be embedded on the system as close to the CPU as main memory, with latencies substantially lower than any other available flash options, offering better performance at a lower solution cost than other embedded flash solutions.”
He said write latency (a critical metric) for IBM eXFlash will be in the 5 to 10 microsecond range, whereas best-of-breed competing mezzanine card and PCIe flash can only offer 15 to 20 microseconds (and external flash storage is slower still). “Additionally, since the DIMMs are directly attached to the memory controller, flash I/O does not compete with other I/O on the system I/O hub and PCIe subsystem, improving overall system performance for heavily-loaded systems. Additional benefits include linear performance scalability as the number of DIMMs increase and optional built-in hardware mirroring of DIMM pairs.”
While not prepared to name names, SanDisk did say other OEMs are evaluating ULLtraDIMM. The company recently pondered the prospects of an all-flash data center, and while unlikely as that will be, certainly in the near future, the likelihood that Big Blue’s server competitors like HP and Dell, will allow it to run away with this segment is equally improbable.
Finally, while the IBM OEM contract is a big deal for both SanDisk and Diablo, like OCZ, there is also a legal cloud involved. Diablo and SanDisk, by way of its acquisition of Smart Storage, are being sued by Netlist, which has accused them of intellectual property theft. SanDisk said the lawsuit has no merit and will be strongly contested.