SLI Technology

Introduction

In the summer of 2004, nVidia released a new technology into the gaming market. The nVidia Corporation is known primarily for developing and supplying GPUs (Graphics Processing Units), motherboard chipsets, and contributing to other forms of multimedia hardware. The latest buzz about nVidia centers around developments made with GPU and chipset technology. These technologies are used in joint operation to produce a gigantic leap forward in gaming hardware horsepower. This technology is called the “Scalable Link Interface”.

Surprisingly, SLI technology is not a new concept. The first line of SLI products were produced by a video card company named 3dfx. SLI was first used in arcade game consoles and other professional markets. 3dfx then released a consumer version of SLI in 1998 with their Voodoo2 video card line, which was called “Scan Line Interleave” at the time. nVidia then reintroduced the basic concept on the PCI Express bus, while ATi still continues to tweak their version of a linked video card system named “CrossFire”. Many gamers who have always used ATi products are debating whether to bite the bullet and go for nVidia’s SLI, or play the waiting game and sit tight for the final release of ATi CrossFire.

nVidia’s new SLI (Scalable Link Interface) technology has brought a new incentive for gamers to invest in nVidia video card technology. Broken down into its simplest concept, SLI allows systems to utilize the power of two identical video cards for a single output display. Utilizing any more than two is merely theoretical (or hypothetical) at this point. The purpose of SLI is to offer better performance per cost of a system as a whole. Typically, a single, significantly more powerful video card rivals the cost of two less powerful cards. Plus, these two cards can be purchased separately (one initially, and the second as a later upgrade), defraying the cost of an expensive gaming system. This certainly helps builders on a lower budget and helps keep an older machine usable for a longer period of time.

With a traditional gaming computer, you would find a motherboard, a CPU, RAM, and a video card making up a system’s core components. SLI technology makes it possible to install two video cards, and have them operate simultaneously for a boost in image rendering performance.

First, we will introduce you to what the original SLI technology was, how it was used, and a brief history leading up to the current form of SLI technology, including current and past market influences leading to its demise and rebirth. This is followed by architecture comparisons between technologies, the performance benefits of current SLI technology, and the hardware requirements for building a computer that would support SLI.

After taking a look at the hardware side of SLI, we will dive into the software side of SLI, which is where the real magic happens. Discussed are SLI’s rendering and Antialiasing methods in detail, plus some comparisons between their respective settings, which are critical pieces of the SLI setup as a whole.

Wrapping up the contextual portion of the document, we end with a brief look at the innovation of gaming technology and with our analysis of the best situation where SLI can be utilized effectively, taking cost vs. performance into account. Performance in this case would equate to how efficient the technology would maintain an acceptable output response. In other words, it must maintain an acceptable frame rate and quality.