What's the Big Deal?

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.

The Program And New HP Business Unit

Over the past months server vendors have been announcing benchmark results for systems incorporating Intel’s high-end x86 CPU, the E7, with HP trumping all existing benchmarks with their recently announced numbers (although, as noted in x86 Servers Hit The High Notes, the results are clustered within a few percent each other). HP recently announced new performance numbers for their ProLiant DL980, their high-end 8-socket x86 server using the newest Intel E7 processors. With up to 10 cores, these new processors can bring up to 80 cores to bear on large problems such as database, ERP and other enterprise applications.

The performance results on the SAP SD 2-Tier benchmark, for example, at 25160 SD users, show a performance improvement of 35% over the previous high-water mark of 18635. The results seem to scale almost exactly with the product of core count x clock speed, indicating that both the system hardware and the supporting OS, in this case Windows Server 2008, are not at their scalability limits. This gives us confidence that subsequent spins of the CPU will in turn yield further performance increases before hitting system of OS limitations. Results from other benchmarks show similar patterns as well.

Key takeaways for I&O professionals include:

• Expect to see at least 25% to 35% throughput improvements in many workloads with systems based on the latest the high-performance PCUs from Intel. In situations where data center space and cooling resources are constrained this can be a significant boost for a same-footprint upgrade of a high-end system.
• For Unix to Linux migrations, target platform scalability continues become less of an issue.

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.

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…