This week, IBM announced its new line of x86 servers, and included among the usual incremental product improvements is a performance game-changer called eXFlash. eXFlash is the first commercially available implantation of the MCS architecture announced last year by Diablo Technologies. 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. Key aspects of the announcement include:
■ Flash DIMMs offer scalable high performance. 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.
■ eXFlash DIMMs are compatible with current software. Part of the magic of MCS flash is that it appears to the OS as a standard block-mode device, so all existing block-mode software will work, including applications, caching and tiering or general storage management software. For IBM users, compatibility with IBM’s storage management and FlashCache Storage Accelerator solutions is guaranteed. Other vendors will face zero to low effort in qualifying their solutions.
As the new year looms, thoughts turn once again to our annual reading of the tea leaves, in this case focused on what I see coming in server land. We’ve just published the full report, Predictions for 2014: Servers & Data Centers, but as teaser, here are a few of the major highlights from the report:
1. Increasing choices in form factor and packaging – I&O pros will have to cope with a proliferation of new form factors, some optimized for dense low-power cloud workloads, some for general purpose legacy IT, and some for horizontal VM clusters (or internal cloud if you prefer). These will continue to appear in an increasing number of variants.
2. ARM – Make or break time is coming, depending on the success of coming 64-bit ARM CPU/SOC designs with full server feature sets including VM support.
3. The beat goes on – Major turn of the great wheel coming for server CPUs in early 2014.
4. Huge potential disruption in flash architecture – Introduction of flash in main memory DIMM slots has the potential to completely disrupt how flash is used in storage tiers, and potentially can break the current storage tiering model, initially physically with the potential to ripple through memory architectures.
Yesterday Intel had a major press and analyst event in San Francisco to talk about their vision for the future of the data center, anchored on what has become in many eyes the virtuous cycle of future infrastructure demand – mobile devices and “the Internet of things” driving cloud resource consumption, which in turn spews out big data which spawns storage and the requirement for yet more computing to analyze it. As usual with these kinds of events from Intel, it was long on serious vision, and strong on strategic positioning but a bit parsimonious on actual future product information with a couple of interesting exceptions.
Content and Core Topics:
No major surprises on the underlying demand-side drivers. The the proliferation of mobile device, the impending Internet of Things and the mountains of big data that they generate will combine to continue to increase demand for cloud-resident infrastructure, particularly servers and storage, both of which present Intel with an opportunity to sell semiconductors. Needless to say, Intel laced their presentations with frequent reminders about who was the king of semiconductor manufacturingJ
My Forrester colleagues Ted Schadler and John McCarthy have written about the differences between Systems of Reference (SoR) and Systems of Engagement (SoE) in the customer-facing systems and mobility, but after further conversations with some very smart people at IBM, I think there are also important reasons for infrastructure architects to understand this dichotomy. Scalable and flexible systems of engagement, engagement, built with the latest in dynamic web technology and the back-end systems of record, highly stateful usually transactional systems designed to keep track of the “true” state of corporate assets are very different animals from an infrastructure standpoint in two fundamental areas:
Suitability to cloud (private or public) deployment – SoE environments, by their nature, are generally constructed using horizontally scalable technologies, generally based on some level of standards including web standards, Linux or Windows OS, and some scalalable middleware that hides the messy details of horizontally scaling a complex application. In addition, the workloads are generally highly parallel, with each individual interaction being of low value. This characteristic leads to very different demands on the necessity for consistency and resiliency.
Background — High Performance Attached Processors Handicapped By Architecture
The application of high-performance accelerators, notably GPUs, GPGPUs (APUs in AMD terminology) to a variety of computing problems has blossomed over the last decade, resulting in ever more affordable compute power for both horizon and mundane problems, along with growing revenue streams for a growing industry ecosystem. Adding heat to an already active mix, Intel’s Xeon Phi accelerators, the most recent addition to the GPU ecosystem, have the potential to speed adoption even further due to hoped-for synergies generated by the immense universe of x86 code that could potentially run on the Xeon Phi cores.
However, despite any potential synergies, GPUs (I will use this term generically to refer to all forms of these attached accelerators as they currently exist in the market) suffer from a fundamental architectural problem — they are very distant, in terms of latency, from the main scalar system memory and are not part of the coherent memory domain. This in turn has major impacts on performance, cost, design of the GPUs, and the structure of the algorithms:
Performance — The latency for memory accesses generally dictated by PCIe latencies, which while much improved over previous generations, are a factor of 100 or more longer than latency from coherent cache or local scalar CPU memory. While clever design and programming, such as overlapping and buffering multiple transfers can hide the latency in a series of transfers, it is difficult to hide the latency for an initial block of data. Even AMD’s integrated APUs, in which the GPU elements are on a common die, do not share a common memory space, and explicit transfers are made in and out of the APU memory.
The industry is abuzz with speculation that IBM will sell its x86 server business to Lenovo. As usual, neither party is talking publicly, but at this point I’d give it a better than even chance, since usually these kind of rumors tend to be based on leaks of real discussions as opposed to being completely delusional fantasies. Usually.
So the obvious question then becomes “Huh?”, or, slightly more eloquently stated, “Why would they do something like that?”. Aside from the possibility that this might all be fantasy, two explanations come to mind:
1. IBM is crazy.
2. IBM is not crazy.
Of the two explanations, I’ll have to lean toward the latter, although we might be dealing with a bit of the “Hey, I’m the new CEO and I’m going to do something really dramatic today” syndrome. IBM sold its PC business to Lenovo to the tune of popular disbelief and dire predictions, and it's doing very well today because it transferred its investments and focus to higher margin business, like servers and services. Lenovo makes low-end servers today that it bootstrapped with IBM licensed technology, and IBM is finding it very hard to compete with Lenovo and other low-cost providers. Maybe the margins on its commodity server business have sunk below some critical internal benchmark for return on investment, and it believes that it can get a better return on its money elsewhere.
In his 1956 dystopian sci-fi novel “The City and the Stars”, Arthur C. Clarke puts forth the fundamental design tenet for making eternal machines, “A machine shall have no moving parts”. To someone from the 1950s current computers would appear to come close to that ideal – the CPUs and memory perform silent magic and can, with some ingenuity, be passively cooled, and invisible electronic signals carry information in and out of them to networks and … oops, to rotating disks, still with us after more than five decades[i]. But, as we all know, salvation has appeared on the horizon in the form of solid-state storage, so called flash storage (actually an idea of several decades standing as well, just not affordable until recently).
The initial substitution of flash for conventional storage yields immediate gratification in the form of lower power, maybe lower cost if used effectively, and higher performance, but the ripple effect benefits of flash can be even more pervasive. However, the implementation of the major architectural changes engendered across the whole IT stack by the use of flash is a difficult conceptual challenge for users and largely addressed only piecemeal by most vendors. Enter IBM and its Flashahead initiative.
What is Happening?
On Friday, April 11, IBM announced a major initiative, to the tune of a spending commitment of $1B, to accelerate the use of flash technology by means of three major programs:
· Fundamental flash R&D
· New storage products built on flash-only memory technology
HP today announced the Moonshot 1500 server, their first official volume product in the Project Moonshot server product family (the initial Redstone, a Calxeda ARM-based server, was only available in limited quantities as a development system), and it represents both a significant product today and a major stake in the ground for future products, both from HP and eventually from competitors. It’s initial attractions – an extreme density low power x86 server platform for a variety of low-to-midrange CPU workloads – hides the fact that it is probably a blueprint for both a family of future products from HP as well as similar products from other vendors.
Geek Stuff – What was Announced
The Moonshot 1500 is a 4.3U enclosure that can contain up to 45 plug-in server cartridges, each one a complete server node with a dual-core Intel Atom 1200 CPU, up to 8 GB of memory and a single disk or SSD device, up to 1 TB, and the servers share common power supplies and cooling. But beyond the density, the real attraction of the MS1500 is its scalable fabric and CPU-agnostic architecture. Embedded in the chassis are multiple fabrics for storage, management and network giving the MS1500 (my acronym, not an official HP label) some of the advantages of a blade server without the advanced management capabilities. At initial shipment, only the network and management fabric will be enabled by the system firmware, with each chassis having up two Gb Ethernet switches (technically they can be configured with one, but nobody will do so), allowing the 45 servers to share uplinks to the enterprise network.
With a couple of months' perspective, I’m pretty convinced that Intel has made a potentially disruptive entry in the market for programmable computational accelerators, often referred to as GPGPUs (General Purpose Graphics Processing Units) in deference to the fact that the market leaders, NVIDIA and AMD, have dominated the segment with parallel computational units derived from high-end GPUs. In late 2012, Intel, referring to the architecture as MIC (Many Independent Cores) introduced the Xeon Phi product, the long-awaited productization of the development project that was known internally (and to the rest of the world as well) as Knight’s Ferry, a MIC coprocessor with up to 62 modified Xeon cores implemented in its latest 22 nm process.
When I returned to Forrester in mid-2010, one of the first blog posts I wrote was about Oracle’s new roadmap for SPARC and Solaris, catalyzed by numerous client inquiries and other interactions in which Oracle’s real level of commitment to future SPARC hardware was the topic of discussion. In most cases I could describe the customer mood as skeptical at best, and panicked and committed to migration off of SPARC and Solaris at worst. Nonetheless, after some time spent with Oracle management, I expressed my improved confidence in the new hardware team that Oracle had assembled and their new roadmap for SPARC processors after the successive debacles of the UltraSPARC-5 and Rock processors under Sun’s stewardship.
Two and a half years later, it is obvious that Oracle has delivered on its commitments regarding SPARC and is continuing its investments in SPARC CPU and system design as well as its Solaris OS technology. The latest evolution of SPARC technology, the SPARC T5 and the soon-to-be-announced M5, continue the evolution and design practices set forth by Oracle’s Rick Hetherington in 2010 — incremental evolution of a common set of SPARC cores, differentiation by variation of core count, threads and cache as opposed to fundamental architecture, and a reliable multi-year performance progression of cores and system scalability.