PCI Express to Punctuate Advances in 2014

The market for PCI Express (PCIe) chips and the systems that use them has been relatively predictable over the past several years, with speed improvements enabling more horsepower, though with the basic usage models being relatively similar from one year – and one generation – to the next.  The year 2014, however, will be more like the punctuated equilibrium that characterizes evolution.  Things remain static for a while, but when they happen they can really happen; PCIe designs are up across a spectrum of market segments and applications.  Advances in PCIe applications that have been incubating for several years are beginning to come to fruition, and 2014 should see a continuation of these opportunities for system designers using PCIe.

Storage has always been a mainstream use of PCIe – but 2014 will take this up a notch.  The enterprise-level solid-state drive (SSD) market has been adopting PCIe because its feature-set is best-suited to connect these storage elements to the rest of the system.  However, the market has been held back by not having a standard way to implement such systems with off-the-shelf building blocks.  There is now a variety of standards that will remedy this -- such as NVMe, SATA Express, and SCSI Express -- created to make these systems easier to implement and be more cost-effective.  The first NVMe-based storage building blocks are just starting to come out, and we expect that in 2014 this market will start to ramp as systems based on the new devices are deployed in larger numbers.

While extensions to the PCIe specification happen on a regular basis, there are few as important as those that deal with reliability, and the new downstream port containment (DPC) extension is a key enhancement.  This update enables more robust handling of errors, which is especially important in the storage market, where data availability and reliability are critical.  As with all the PCIe advances discussed here, DPC has been in the works for a while, but 2014 is when the building blocks will be available so that actual systems can be deployed that make use of its capability.  This will lead to more reliable PCIe-based storage systems, broadening the number of markets where the technology can be used.

And in addition to the basic silicon building blocks, the new M.2 specification (once known as the Next Generation Form Factor) will drive the adoption of highly dense SSD-based storage on a variety of platforms.  While not specifically dedicated to PCIe, this form factor accommodates PCIe-based SSD devices, and since PCIe is rapidly becoming the standard protocol for those devices, M.2 will provide a turbo-charged enhancement to an already powerful engine.

Some designers are focused on the new mobile-oriented M-PCIe standard which was developed to allow PCIe to better penetrate the power-critical consumer market.  This area has been ripe for picking for a long time, since the alternative methods to achieve power efficiency entail moving between different protocols.  New designs are expected to extend PCIe further in the mobile applications.

PCIe has traditionally been viewed as an inside-the-box technology, but in 2014 we’ll witness an expansion of this viewpoint as general-purpose deployments of PCIe as a fabric rollout, such those based on PLX’s ExpressFabric technology.  While the protocol has already penetrated most applications inside the box, PCIe is expected to develop traction externally by connecting all the boxes within racks -- thus eliminating costly and power hungry protocol translation hardware -- while seamlessly working with Ethernet rack-to-rack.  With some straightforward extensions based on the existing standard, PCIe can be deployed as a low-power, cost-effective, high-performance fabric.

Some interesting developments in cabling via PCIe are expected to take root.  Another extension to the PCIe standard is called SRIS, which enables clock-less cables to be used with off-the-shelf products.  Additionally, a new PCIe cable named OCuLink will enable mainstream, cost-effective systems to be built where PCIe goes from one box to another.  The new cable allows both copper and optical links to be deployed with PCIe-based systems.  Optical connectivity with PCIe has been demonstrated for several years, and given the amount of activity at key vendors, 2014 might be the year that this approach becomes more mainstream.

Finally, one trend we expect to see emerge in 2014 is the use of PCIe in microserver-based systems.  Every element in a microserver – processor, communications device, and storage – has PCIe as at least one of its interfaces.  So, using PCIe as the pathway builds on the natural advantage of these types of systems: low power, low cost, and flexibility.

2014 looks to be a year in which PCIe’s natural advantages merge with new standards that tackle the industry’s ever-evolving demand for performance, power efficiency and cost savings.