The server market is at a potential inflection point, with a new breed of ARM-based microserver vendors challenging the status quo, particularly for cloud computing. We survey 20 modern processors to understand the options for alternative architectures. To achieve disruptive performance, microserver vendors must deeply specialize in particular workloads. However, there is a trade-off between differentiation and market breadth. As the handful of microserver startups are culled to 1-2 viable vendors, only the companies which deliver compelling advantages to significant markets will survive.

The iPad 3 was an influential and successful tablet, but an excellent example of an unbalanced system. In particular, the superb Retina display was not adequately matched by the GPU of the A5X, and represented a step backwards in terms of graphics capabilities. This article explores the challenges of designing innovative products given the underlying technical constraints, through the lens of the iPad 3 and its successors.

Near-threshold voltage computing extends the voltage scaling associated with Moore’s Law and dramatically improves power and energy efficiency. The technology is superb for throughput, at the cost of latency, and best suited to Intel’s products for HPC and mobile graphics.

The new ARMv8 architecture is classically British; a clean and elegant 64-bit instruction set, with compatibility for 32-bit software. The 64-bit mode eliminates many complicated and awkward features and will foster a larger and more diverse ARM ecosystem with new licensees and applications.

New compute efficiency data shows GPUs with a clear edge over CPUs, but the gap is narrowing as CPUs adopt wide vectors (e.g. AVX). Surprisingly, a throughput CPU is the most energy efficient processor, offering hope for future architectures. Our data also shows some advantages of AMD’s Bulldozer, and the overhead associated with highly scalable server CPUs.

With all the recent changes, AMD seems like a ship adrift at sea with no clear strategy or vision. We look at AMD and where they are likely to head in the coming years for tablets and phones and explain why they will stick with x86, rather than embrace ARM as some have suggested.

Highlights of the upcoming 2012 ISSCC include the first 22nm disclosures from Intel and several SoC papers from AMD, Cavium Networks and Oracle. Looking out further to the future, the clear focus is power consumption. There are several papers from Intel on low-power logic, one from IBM discussing 3D integration of embedded DRAM and a third from Fujitsu on system level power for the K supercomputer.

Nvidia’s Kal-El sports a novel 5th ‘companion’ core to lower idle power. We look at the trade-offs and benefits to this approach and explain why it will be a strong tablet SoC, but only an incremental gain for smartphones.

AMD’s Hot Chips presentation delved into Llano, the first mainstream Fusion product, with details and results for power management. Previous disclosures painted a poor picture, which is far from the truth. Given the older CPU and GPU designs and time-to-market pressure, the results are quite good. Llano’s power management focuses on the most important aspects and is a solid foundation for future generations that will be much more power aware and optimized.

Enthusiasts and engineers know cooling is vital; it raises frequency and dramatically lowers power by reducing CPU or GPU temperatures. The world’s fastest supercomputer shows that thermal management can increase CPU performance/watt by 20% and cooling is critical for 3D integration and Moore’s Law.

Editor’s Picks

Intel’s Haswell CPU Microarchitecture

By David Kanter