Getting on board the PCI express

Post, Nov, 2004 by Randall G. Simpson

If you've been into digital content creation for any length of time, you've gotten used to constant revolutions and evolutions of equipment and techniques. The only constant, as the cliche goes, is change itself. Nowhere is this change more apparent then in the most essential tool of post production--the computer workstation. More specifically, nowhere is change more literally visible than in the piece of computer hardware that has the most immediate visual impact on the quality of images generated from the workstation--its graphics card.

Under the backdrop of constant change, yet another new generation of graphics accelerators are entering the marketplace. Though PCI Express will take a few years to totally replace the older AGP and PCI standards, this new architecture will ultimately change the way digital artists, digital film and video post production professionals work, reaching down to the change the design of software application themselves.

OLD AND NEW

Graphics cards have evolved right along with computer bus and processor technology, with the trend to faster and wider data pipes and ever-increasing amounts of memory. It's amazing to think that way back in the 1980s when those brainy and farsighted computer engineers were first thinking about doing post on computers, they were stuck with the ancient ISA (Industry Standard Architecture) bus system and associated video cards. These old trains initially had a whopping 8MHz (later up to 16MHz) clockspeed and some even topped out with an amazing IMB of RAM! Next came a few fairly short-lived trains called the VESA Local Bus and EISA, but they were sidelined quickly for the revolutionary PCI (Peripheral Component Interconnect) bus. These amazing new cards were up to 10 times faster than ISA and boasted up to 133MB/s bandwidth. PCI evolved and increased performance levels frequently until yet a new train appeared on the scene. This new train was developed to take the data strain off the PCI bus by creating a dedicated data pathway for graphics cards. The Accelerated Graphics Port, or AGP cards, came to market in the mid-1990s and vastly improved performance for many applications, especially 3D. When they first entered the market, these cards ran double the PCI bandwidth or 266MB/s. AGP evolved over the years and we saw AGP 2X and then 4X and then finally AGP 8X, each boasting ever increasing new benchmarks for speed and bandwidth. Enter now, PCI Express. It instantly doubles the potential bandwidth over the AGP 8X standard with up to 16 lanes or channels for data flow.

BANDWIDTH TO HANDLE MULTI-STREAM HD

The average AGP 8X graphic cards is adequate for running a few streams of normal standard definition video or even a single stream of HD. The AGP pipeline starts to become more of a bottleneck however when faced with multiple streams of high def content. The realities of HD on the desktop simply dictate the necessity of the greater bandwidth that PCI Express offers. PCI Express is the key to true multi-stream HD apps but has multiple ways it can be implemented and customized to different bandwidth requirements. On 1X implementation it has about 500MB/s bandwidth and can be scaled up to the 16X implementation with 8000MB/s bandwidth! Compare this to AGP 8X with about 2112 MB/s. PCI Express has the bandwidth for multiple HD streams. If you plan on doing any serious HD work, you will eventually want and need PCI Express.

WHO'S ON BOARD THE PCI EXPRESS?

There are really only three primary players in the professional workstation graphics marketplace. It is a marketplace that is increasingly focused on supporting the acceleration of workstation applications using the OpenGL and Microsoft DirectX standards. Nvidia currently owns the lion's share of the overall market, followed by ATI Technologies and then 3DLabs. Matrox could be considered as a very minor fourth player, though admittedly this privately owned Canadian company seems focused on different markets than the other three, and I include it here mainly because they do offer some unique DCC-related products that fill a niche in the editing and multi-monitor environment.

NVIDIA

Nvidia (www.nvidia.com) has taken the industry by storm over the past four or five years. Their very successful Nvidia Quadro FX family has become a defacto standard in many professional workstations. They have introduced entire families of boards to fit nearly every performance and price point. Added to Nvidia's comprehensive family of products is their successful and stable Unified Driver Architecture (UDA) that allows all of their products to be driven from a single software application with sophisticated programmability. For the information technology manager responsible for large operations and many systems to attend to, Nvidia's unified driver approach is exactly the right tool.

But of course Nvidia's unified driver approach wouldn't be as appealing if they didn't have some extraordinary graphics accelerators to drive. The high-end Nvidia Quadro FX solutions took AGP 8X graphics to new levels of performance. While Jeff Brown. Nvidia's GM of professional graphics product management, wouldn't absolutely say there would be no more new AGP offerings from the company, he made it pretty clear that PCI Express is where the future is. "During this period of transition to PCI Express, we expect our AGP products to continue to be strong sellers. Brown comments. But everyone knows where the industry is headed."