Introduction

Ever since it was announced earlier this summer, NVIDIA’s SLI (scaleable link interface) technology has been turning heads. The concept is simple, by pairing two PCI Express variants of GeForce 6600 GT/6800 GT/6800 Ultra cards together you’ll get nearly double the performance. The cards work in concert with one another, with the work split among the cards horizontally across the screen. One card takes the upper portion while the second card takes the lower segment.

It’s important to note that the screen isn’t necessarily split exactly in half. Since scene complexity can vary from the top of the screen to the bottom (say for instance a scene with thick jungle foliage on the bottom of the screen and a clear blue sky up top) dynamic load-balancing algorithms are used to ensure that the work is split optimally between both cards.

The real beauty of SLI from a cost-conscious perspective is that your system can be upgraded in stages. You can buy one card now, and later, when more demanding games are released or your budget allows, drop in a second card of the same type and card manufacturer for up to a 1.5x performance increase (the actual amount will vary depending on the settings used and the game itself). Then, when the next generation cards come out, the entire process can be repeated again, ensuring you get the maximum life out of your SLI motherboard. The idea of adding a second card to nearly double performance is enticing to many gamers but the million dollar question has been when will it become available?

Today NVIDIA takes one step closer to bringing SLI to reality with the announcement of their SLI certification program.

We first described the process in our nForce4 Ultra preview article last month, but basically NVIDIA and its partners are working hard to ensure that the SLI-capable parts work well with each other. According to the NVIDIA press release: “The NVIDIA SLI certification process includes complex testing and analysis to ensure electrical, mechanical, and thermal compatibility. For PC system integrators, NVIDIA will check thermal measurements and ensure additional shock, power, and vibration tests are conducted on multiple components, including hard drives, fans, and power supplies. For application developers who wish to tune their applications to run best under SLI configurations, NVIDIA is providing performance tools and a complete SLI development system that allow their content to take advantage of additional detail levels and resolutions not previously available to single GPU systems.”

Hardware components (motherboards and graphics cards) that are installed by do-it-yourselfers to make a potential SLI system will be labeled under the “NVIDIA SLI Ready” logo, while complete fully-configured SLI systems end user’s can purchase at retail will fall under the “NVIDIA SLI” logo. These systems will boast full SLI support out-of-the-box with all the proper hardware and software pre-installed by the manufacturer. NVIDIA has already lined up the following system builders:

ABS

Alienware Corporation

Atelco

Cyberpower

EID

Falcon Northwest Computer Systems

iBuypower

IHDE

ISM

Network Technical

NTT

Olidata

Overdrive PC

Paradigit

Polywell

Scan

Topnotch

Velocity Micro

VoodooPC

The following motherboard manufacturers have also signed on (so far) with nForce4 SLI products in the pipeline:

ABIT Computer Corporation

ASUS

DFI

EPoX Computer Co. Ltd.

Gigabyte Technology Co., Ltd

Iwill Corporation

MSI Computer Corporation

We’ve heard that ASUS and MSI will likely be first out of the gates with nForce4 SLI motherboards, with the others to follow at the beginning of next year. The first motherboards should be hitting retail at the end of this month.

On the graphics side, it’s no surprise to see that all of NVIDIA’s biggest partners have signed on:

Aopen America, Inc

ASUS Computer International

BFG Technologies, Inc.

eVGA.com Corporation

Gainward Co. Ltd.

Jaton

Gigabyte Technology Co., Ltd

Leadtek Research Inc.

MSI Computer Corporation

Palit Microsystems, Inc.

Peach

PNY Technologies, Inc.

XFX

SLI capable graphics cards have been shipping for some time now in the form of the PCI Express GeForce 6800 GT, while allocation of GeForce 6800 Ultra and 6600 GT is expected to pick up in anticipation of SLI making its retail debut. The US branch offices of many of the aforementioned companies have received their first shipments of GeForce 6600 GT cards and we should have the first wave of board reviews going up later this month.

Summary

Today’s announcement brings consumers one step closer to getting their hands on SLI technology. By establishing a certification process, NVIDIA can ensure that the underlying hardware has been designed and tested to work properly with SLI.

NVIDIA plans to establish a special SLI section on their nZone website with a list of all compatible hardware that end user’s can use as a resource to determine which components have NVIDIA’s official seal of approval, meanwhile, the Average Joe can just look for the NVIDIA SLI logo when he’s shopping at his local retailer or specialty computer shop. We’ve heard that technically SLI should work with cards of the same type, regardless of manufacturer (say for instance, combining a Leadtek GeForce 6800 GT with an ASUS 6800 GT), but it’s possible that NVIDIA may include special hooks inside their driver that prevent consumers from cross-combining manufacturers to make certain that everything works properly with SLI upon launch.

In any case, if you’re looking to setup an SLI system, NVIDIA’s certification and logo program has just made things easier. When purchasing intended hardware, just look for the proper logo and update to the latest official NVIDIA driver (currently ForceWare 66.93) and you should be good to go. Now we just need the SLI motherboards to ship!