In late 2010 I noted that startup SeaMicro had introduced an ultra-dense server using Intel Atom chips in an innovative fabric-based architecture that allowed them to factor out much of the power overhead from a large multi-CPU server ( http://blogs.forrester.com/richard_fichera/10-09-21-little_servers_big_applications_intel_developer_forum). Along with many observers, I noted that the original SeaMicro server was well-suited to many light-weight edge processing tasks, but that the system would not support more traditional compute-intensive tasks due to the performance of the Atom core. I was, however, quite taken with the basic architecture, which uses a proprietary high-speed (1.28 Tb/s) 3D mesh interconnect to allow the CPU cores to share network, BIOS and disk resources that are normally replicated on a per-server in conventional designs, with commensurate reductions in power and an increase in density.
Emerging ARM server Calxeda has been hinting for some time that they had a significant partnership announcement in the works, and while we didn’t necessarily not believe them, we hear a lot of claims from startups telling us to “stay tuned” for something big. Sometimes they pan out, sometimes they simply go away. But this morning Calxeda surpassed our expectations by unveiling just one major systems partner – but it just happens to be Hewlett Packard, which dominates the WW market for x86 servers.
At its core (unintended but not bad pun), the HP Hyperscale business unit Project Moonshot and Calxeda’s server technology are about improving the efficiency of web and cloud workloads, and promises improvements in excess of 90% in power efficiency and similar improvements in physical density compared with current x86 solutions. As I noted in my first post on ARM servers and other documents, even if these estimates turn out to be exaggerated, there is still a generous window within which to do much, much, better than current technologies. And workloads (such as memcache, Hadoop, static web servers) will be selected for their fit to this new platform, so the workloads that run on these new platforms will potentially come close to the cases quoted by HP and Calxeda.
Intel has been publishing research for about a decade on what they call “3D Trigate” transistors, which held out the hope for both improved performance as well as power efficiency. Today Intel revealed details of its commercialization of this research in its upcoming 22 nm process as well as demonstrating actual systems based on 22 nm CPU parts.
The new products, under the internal name of “Ivy Bridge”, are the process shrink of the recently announced Sandy Bridge architecture in the next “Tock” cycle of the famous Intel “Tick-Tock” design methodology, where the “Tick” is a new optimized architecture and the “Tock” is the shrinking of this architecture onto then next generation semiconductor process.
What makes these Trigate transistors so innovative is the fact that they change the fundamental geometry of the semiconductors from a basically flat “planar” design to one with more vertical structure, earning them the description of “3D”. For users the concepts are simpler to understand – this new transistor design, which will become the standard across all of Intel’s products moving forward, delivers some fundamental benefits to CPUs implemented with them:
Leakage current is reduced to near zero, resulting in very efficient operation for system in an idle state.
Power consumption at equivalent performance is reduced by approximately 50% from Sandy Bridge’s already improved results with its 32 nm process.
Calxeda, one of the most visible stealth mode startups in the industry, has finally given us an initial peek at the first iteration of its server plans, and they both meet our inflated expectations from this ARM server startup and validate some of the initial claims of ARM proponents.
While still holding their actual delivery dates and details of specifications close to their vest, Calxeda did reveal the following cards from their hand:
The first reference design, which will be provided to OEM partners as well as delivered directly to selected end users and developers, will be based on an ARM Cortex A9 quad-core SOC design.
The SOC, as Calxeda will demonstrate with one of its reference designs, will enable OEMs to design servers as dense as 120 ARM quad-core nodes (480 cores) in a 2U enclosure, with an average consumption of about 5 watts per node (1.25 watts per core) including DRAM.
While not forthcoming with details about the performance, topology or protocols, the SOC will contain an embedded fabric for the individual quad-core SOC servers to communicate with each other.
Most significantly for prospective users, Calxeda is claiming, and has some convincing models to back up these claims, that they will provide a performance advantage of 5X to 10X the performance/watt and (even higher when price is factored in for a metric of performance/watt/$) of any products they expect to see when they bring the product to market.
Intel, despite a popular tendency to associate a dominant market position with indifference to competitive threats, has not been sitting still waiting for the ARM server phenomenon to engulf them in a wave of ultra-low-power servers. Intel is fiercely competitive, and it would be silly for any new entrants to assume that Intel will ignore a threat to the heart of a high-growth segment.
In 2009, Intel released a microserver specification for compact low-power servers, and along with competitor AMD, it has been aggressive in driving down the power envelope of its mainstream multicore x86 server products. Recent momentum behind ARM-based servers has heated this potential competition up, however, and Intel has taken the fight deeper into the low-power realm with the recent introduction of the N570, a an existing embedded low-power processor, as a server CPU aimed squarely at emerging ultra-low-power and dense servers. The N570, a dual-core Atom processor, is being currently used by a single server partner, ultra-dense server manufacturer SeaMicro (see Little Servers For Big Applications At Intel Developer Forum), and will allow them to deliver their current 512 Atom cores with half the number of CPU components and some power savings.
Technically, the N570 is a dual-core Atom CPU with 64 bit arithmetic, a differentiator against ARM, and the same 32-bit (4 GB) physical memory limitations as current ARM designs, and it should have a power dissipation of between 8 and 10 watts.
Last week IBM and ARM Holdings Plc quietly announced a continuation of their collaboration on advanced process technology, this time with a stated goal of developing ARM IP optimized for IBM physical processes down to a future 14 nm size. The two companies have been collaborating on semiconductors and SOC design since 2007, and this extension has several important ramifications for both companies and their competitors.
It is a clear indication that IBM retains a major interest in low-power and mobile computing, despite its previous divestment of its desktop and laptop computers to Lenovo, and that it will be in a position to harvest this technology, particularly ARM's modular approach to composing SOC systems, for future productization.
For ARM, the implications are clear. Its latest announced product, the Cortex A15, which will probably appear in system-level products in approximately 2013, will be initially produced in 32 nm with a roadmap to 20nm. The existence of a roadmap to a potential 14 nm product serves notice that the new ARM architecture will have a process roadmap that will keep it on Intel’s heels for another decade. ARM has parallel alliances with TSMC and Samsung as well, and there is no reason to think that these will not be extended, but the IBM alliance is an additional insurance policy. As well as a source of semiconductor technology, IBM has a deep well of systems and CPU IP that certainly cannot hurt ARM.
From nothing more than an outlandish speculation, the prospects for a new entrant into the volume Linux and Windows server space have suddenly become much more concrete, culminating in an immense buzz at CES as numerous players, including NVIDIA and Microsoft, stoked the fires with innuendo, announcements, and demos.
Consumers of x86 servers are always on the lookout for faster, cheaper, and more power-efficient servers. In the event that they can’t get all three, the combination of cheaper and more energy-efficient seems to be attractive to a large enough chunk of the market to have motivated Intel, AMD, and all their system partners to develop low-power chips and servers designed for high density compute and web/cloud environments. Up until now the debate was Intel versus AMD, and low power meant a CPU with four cores and a power dissipation of 35 – 65 Watts.
The Promised Land
The performance trajectory of processors that were formerly purely mobile device processors, notably the ARM Cortex, has suddenly introduced a new potential option into the collective industry mindset. But is this even a reasonable proposition, and if so, what does it take for it to become a reality?
Our first item of business is to figure out whether or not it even makes sense to think about these CPUs as server processors. My quick take is yes, with some caveats. The latest ARM offering is the Cortex A9, with vendors offering dual core products at up to 1.2 GHz currently (the architecture claims scalability to four cores and 2 GHz). It draws approximately 2W, much less than any single core x86 CPU, and a multi-core version should be able to execute any reasonable web workload. Coupled with the promise of embedded GPUs, the notion of a server that consumes much less power than even the lowest power x86 begins to look attractive. But…