Previously, Apple’s iPhones and iPads used PowerVR GPUs from Imagination Technologies for graphics. Based on our analysis, Apple has created a custom GPU that powers the A8, A9, and 10 processors, shipping in the iPhone 6 and later models, and some iPads. Using public documents, we demonstrate that the programmable shader cores inside Apple’s GPU are different from Imagination Technologies’ PowerVR and offer superior 16-bit floating-point performance and data conversion functions. We further believe that Apple has also developed a custom shader compiler and graphics driver. The proprietary design enables Apple to deliver best-in-class performance for graphics, and other tasks that use the GPU, such as image processing and machine learning.
Starting with the Maxwell GM20x architecture, Nvidia high-performance GPUs have borrowed techniques from low-power mobile graphics architectures. Specifically, Maxwell and Pascal use tile-based immediate-mode rasterizers that buffer pixel output, instead of conventional full-screen immediate-mode rasterizers. Using simple DirectX shaders, we demonstrate the tile-based rasterization in Nvidia’s Maxwell and Pascal GPUs and contrast this behavior to the immediate-mode rasterizer used by AMD.
On the eve of the 50th anniversary of Moore’s Law, the future of silicon CMOS is an open question. With rising costs and uncertain benefits, some semiconductor companies have questioned the wisdom of pursuing further scaling. I predict that Intel’s 10nm process technology will use Quantum Well FETs (QWFETs) with a 3D fin geometry, InGaAs for the NFET channel, and strained Germanium for the PFET channel, enabling lower voltage and more energy efficient transistors in 2016, and the rest of the industry will follow suit at the 7nm node.
My favorite paper from the ISSCC processor session describes an adaptive clocking technique implemented in AMD’s 28nm Steamroller core that compensates for power supply noise. Initial results show a 10-20% decrease in power consumption from reducing the voltage, with no loss in performance. This elegant technique is likely to be adopted across AMD’s entire product line including GPUs, x86 CPUs, ARM-based CPUs, and other critical blocks in highly integrated SoCs.
Jaguar is AMD’s first 28nm processor, a compact 3.1mm2 design that targets 2-25W devices. It is a derivative of the earlier 40nm Bobcat, a fully out-of-order two issue design, with significant improvements in instruction set architecture and implementation. Some of the highlights include support for AVX, wider 128-bit datapaths, and a higher performance L2 cache. Jaguar is already shipping in several AMD SoCs targeted at tablets, notebooks, microservers, and desktops. However, it is far more prominent as the CPU powering the Sony Playstation 4 and Microsoft Xbox One.
As of January, 2014 I joined the Linley Group as an analyst and senior editor of the Microprocessor Report (MPR), where I am responsible for PC and server processors, and will be lending a hand with graphics, power management, and mobile devices. I will continue to write shorter articles at RWT and share my thoughts on the industry, but in a fashion that does not conflict with my editorial responsibilities. I will also continue to provide consulting to the industry focusing on intellectual property, as well as technical and competitive analysis.
The 14nm Knights Landing leverages Intel’s resources with a laser-like focus on HPC to deliver a massive improvement over the previous generation. The building block of this architecture is a pair of Silvermont-inspired CPUs with wide vector units and most importantly, a brand new cache hierarchy, on-die fabric, and system infrastructure that is shared with Skylake. This article is an in-depth analysis and prediction of the Knights Landing architecture.
Knights Landing is Intel’s first clean sheet redesign of the Larrabee family, targeted at throughput computing and manufactured on a 14nm process with products expected in late 2014 or early 2015. The adoption of AVX3, on-package embedded DRAM, and bootable products have been disclosed, but most details are unknown. This article analyzes the options available for the Knights Landing CPU core and explains why Intel’s existing cores are a poor fit for the target workloads, concluding that the most likely outcome is a new custom core for Knights Landing.
Silvermont is Intel’s first CPU core tailored for power efficient applications such as smartphones, tablets, and microservers. The 22nm microarchitecture features updated instruction set extensions, full out-of-order execution with a tightly coupled L2 cache, aggressive power management, and a new high performance SoC fabric. These enhancements deliver tremendous performance and frequency gains over the aging Atom core, putting Intel’s mobile strategy in a more competitive position.
Graphics is a focal point of the upcoming Haswell platform, necessitating a high bandwidth memory solution. To deliver high performance Intel is returning to the DRAM market, which it exited in 1985. The memory that ships with Haswell will be a custom embedded DRAM mounted in the package and manufactured on a variant of Intel’s 22nm process. By avoiding the commodity memory market, Intel will preserve high margins by cannibalizing discrete GPUs and dedicated graphics memory.