GeForce 9800 GTX+ SLI review (plus model)

Graphics cards 1048 Page 2 of 8 Published by

teaser

2 - SLI explained and Installation

So today we look at what roughly 450 USD of GPUs will ring us in terms of SLI performance. But what is SLI precisely ?

SLi Explained

Much like ATi's Crossfire, NVIDIA SLI is a situation where you add a second similar generation graphics card (or in more GPUs) to the one you already have in your PC and effectively try to double, triple or even quadruple your raw rendering gaming performance. Today for example we place two NVIDIA graphics cards into a SLI compatible mainboard. We bridge them together, install drivers after which most games can take advantage of the extra horsepower we just added into the system.

The idea is not new at all ... if you are familiar with the hardware developments over the past couple of years you'll remember that 3dfx had a very familiar concept with the Voodoo 2 graphics cards series. There are multiple ways to manage two cards rendering one frame; think of Supertiling, it's a popular form of rendering. Alternate frame Rendering, each card will render a frame (even/uneven) or Split Frame rendering, simply one GPU renders the upper or the lower part of the frame. So you see there are many methods where two or more GPUs can be utilized to bring you a substantial gain in performance.

This review will show SLI performance results throughout the benchmark sessions based on two GPUs rendering the game, and later on in the article even three GPUs rending your games.

IMG_0079.jpgThey look just like identical twins don't they ?

Gettin' down to business - How to setup SLI

Typically I want articles as this one to be some sort of small do-it-yourself guide, so let's talk a little about installation. That way you can replicate the situation at hand at home.

First off we are dealing with really high-end gear today. I do recommend (pun intended) you to have two x16 PCIe slots on your NVIDIA nForce mainboard. Our test will be conducted on a nForce 680i SLI mainboard, which a lot of you guys have as well.

Albatron nForce 680i SLI mainboard review

We insert the two cards into the upper and lower x16 PCIe slot.

Now it's a question of connecting the power supply connectors. Make note of the fact that for two GeForce 9800 GTX+ cards you'll need the PSU to be able to supply 2x dual 6-pin PCIe graphics connectors, that's four in total. If your PSu only has two, don't worry, with each card you will receive one Molex to 6-pin converter, though that would look a little less aesthetically pleasing.

Today we used the BFG 800 Watt ES PSU (read review); perfectly stable, life-time warranty and it already has these connectors on board. So no need for nasty looking splitter cables etc.

My rule for a good PSU in this class of gaming: GeForce 9800 GTX+ SLI requires you to have a 650 Watt power supply unit at minimum if you use it in a high-end system. When you go nuts with 3way SLI, seriously a 800 to a kilowatt PSU is my recommendation. For Triple SLI we used an Enermax Galaxy 1000 Watt PSU (review here), which was perfectly stable including a massive system overclock. 60 AMPs here on the 12 volts rail is nothing to be ashamed about.

Once you have your system ready you can have SLI powered up and ready to roll within a minute, as it really is that easy to do. Now you just need to install the latest drivers, give her a reboot and you are good to go.

After windows rebooted the NVIDIA Control Panel will ask you if you have/want SLI enabled. If not, just pop into the NVIDIA control panel and enable it manually.

bottom3.jpg

Share this content
Twitter Facebook Reddit WhatsApp Email Print