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…
Intel today officially announced the first products based on the much-discussed Sandy Bridge CPU architecture, and first impressions are highly favorable, with my take being that Sandy Bridge represents the first step in a very aggressive product road map for Intel in 2011.
Sandy Bridge is the next architectural spin after Intel’s Westmere shrink of the predecessor Nehalem architecture (the “tick” in Intel’s famous “tick-tock” progression of architectural changes followed by process shrink) and incorporates some major innovations compared to the previous architecture:
Minor but in toto significant changes to many aspects of the low-level microarchitecture – more registers, better prefetch, changes to the way instructions and operands are decode, cached and written back to registers and cache.
Major changes in integration of functions on the CPU die – Almost all major subsystems, including CPU, memory controller, graphics controller and PCIe controller, are now integrated onto the same die, along with the ability to share data with much lower latency than in previous generations. In addition to more efficient data sharing, this level of integration allows for better power efficiency.
Improvements to media processing – A dedicated video transcoding engine and an extended vector instruction set for media and floating point calculations improves Sandy Bridge capabilities in several major application domains.