Intel announced its long-awaited Silvermont overhaul of the Intel Atom core, based on 22nm-fabricated, Tri-Gate 3D transistors. Aimed primarily at smartphones and tablets, the Silvermont supports up to eight cores per SOC (system-on-chip) and promises to offer about 3x the peak performance of the current Atoms or up to 5x their power efficiency.

The new Silvermont core, which updates the Atom’s earlier 32nm Saltwell architecture, will appear in a variety of SOC models that will begin appearing by year’s end, says Intel. The core will be revised with architecture updates every year. The first update will be a 14nm Airmont design due in 2014.

The promised 5x power efficiency enhancements should help Intel compete with ARM Cortex-A9 and -A15 SOCs in mobile devices. While Silvermont should find its way into a wide variety of embedded products, all the way up to ultrabooks and micro-servers, the main focus is on smartphones and tablets, says the company.

Planned Silvermont SOC variants
(click image to enlarge; source: Intel)

An already sampling “Bay Trail” quad-core SOC is set to appear in tablets for year-end holiday sales, and an “Avoton” SOC will ship to customers by year’s end and appear the following year in micro-servers, storage systems, and scale-out datacenter equipment. A Rangeley SOC should follow around the same time, designed for network and communication infrastructure, such as low- and mid-range routers, switches, and security appliances.

A Silvermont-based Merrifield SOC aimed at smartphones will follow in 2014, along with an unnamed automotive SOC. Merrifield will “enable increased performance and battery life over current-generation products and brings support for context aware and personal services, ultra-fast connections for Web streaming, and increased data, device and privacy protection,” states Intel. All of the Silvermont SOCs will support Linux, Android, and Windows.

The Silvermont performance and power improvements, which are said to provide a sliding range of up to three times the performance of current Medfield Atoms or up to five times the power efficiency, stem primarily from its 22nm fabrication and Tri-Gate non-planar transistor technology. The latter is referred to as a 3D chip technology because it takes advantage of the greater surface area supplied by 34nm-high fins that rise from the surface. The Tri-Gate technology can improve transistor performance or decrease power, but is especially effective in power savings, which are further enhanced with the 22nm process.

Silvermont core block diagram
(click image to enlarge; source: Intel)

Additional new features of the Silvermont architecture include:

• Processing — Silvermont offers an out-of-order execution engine optimized for single-threaded performance, as well as a macro operation execution pipeline, improved instruction latencies and throughput, and “smart” pipeline resource management. Other features are said to include more efficient branch processing, a faster recovery pipeline, and out of order memory transactions.
  
  
  Comparison of Silvermont and Saltwell pipelines
  (click image to enlarge; source: Intel)
  

• Multicore — The new multicore and system fabric architecture is scalable up to eight cores designed for higher bandwidth, lower latency and more efficient out-of-order support, says Intel. The architecture is based on two-core “modules,” featuring tightly coupled second-level cache up to 1MB, as well as a dedicated point-to-point interface to the SOC fabric.
  
  
  Silvermont’s modular multicore architecture
  (click image to enlarge)
  

• Security — New IA instructions similar to those in Core Westmere processors are designed for enhanced performance, virtualization and security management, building on Intel’s existing support for 64-bit systems. These include real-time instruction tracing for performance, Intel CT-x2 for virtualization, and AESNI, Intel Secure Key, and Intel OS Guard for security.

• Power management — Enhanced power management capabilities are said to include Intel Burst Technology 2.0, which manages burst frequency in hardware based on thermal, electrical, and power delivery constraints. It supports power sharing between CPU cores as well as GPUs, and features dynamic adjustments of burst operating points.
  
  
  Burst mode improvements
  (click image to enlarge; source: Intel)
  

  Other power management improvements include low-power C states with enhanced C6 modes and fine-grained power gating. A wider dynamic operating range exploits Intel’s 3D transistors, which also enable low leakage and low voltage operation. In addition, custom arrays and libraries are said to be optimized for power and performance.

Silvermont performance comparisons
(click images to enlarge; source: Intel)

The 22nm Tri-Gate process first appeared last year in Intel’s latest Ivy Bridge Core processors using the Haswell architecture. Now Intel has tuned the process for lower power consumption more suitable to the Atom embedded and mobile market. According to Intel, its Haswell Core processors will be offered in more power efficient mobile-focused versions by year’s end. Intel also announced it will at some point move its Xeon processor families to a 22nm process, with resulting improvements in performance per Watt.

According to an Anandtech report, it is “extremely likely” Silvermont will drive power levels down to well below any current ARM processor, including Qualcomm’s industry-leading 28nm Krait 200 core found in the Snapdragon S4 Pro. If so, that could be a remarkable game changer for Intel, depending on the pricing. Current Medfield Atom processors have appeared on a few Android smartphones such as the zippy, 2GHz Motorola Razr i, but pricing has been on the high side, and the improved battery life has yet to match major ARM-based Android competitors.

More information on Intel’s new Silvermont architecture may be found in the Intel Silvermont announcement.