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NVIDIA GeForce 7900 GTX, 7900 GT and 7600 GT Preview

by Ryszard Sommefeldt on 9 March 2006, 14:05

Tags: Nvidia Geforce 7900 GTX, NVIDIA (NASDAQ:NVDA)

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Introduction

Much has been said recently concerning the features and configuration of NVIDIA's next generation GPU products, and the performance of the flagship SKUs they're likely to power. Knowing NVIDIA were moving to 90nm, speculation has been rife about how the Californian graphics giant would use the inherent benefits of a smaller, higher-speed production process.

Using TSMC as a partner once again, the '90GT' process offered by Taiwan's premier semiconductor fabricator gives NVIDIA new avenues to explore when walking the world of die space utilisation and physical chip characteristics, just as it has given ATI in recent months.

Shorter gate length, less voltage and higher possible clock rates opens up a Pandora's box for any chip maker, in terms of moving on a product range in evolutionary steps. Power usage and heat output tradeoffs take on different profiles, meaning you can often move further along the performance curve for a given thermal output.

Increasing that performance via die utilisation and frequency, while simultaneously staying inside those same limits, is the game that's played.

If extra heat output can be tolerated, chips can be made more complex and clock rates can be turned up. NVIDIA's process usage decisions were therefore going to define how their new chips look, and it's those decisions that were second guessed as analysis of what the company were likely to do took place.

Moving from 110nm to 90nm throws up the obvious: Would they make G70 wider? How would it clock? Would NV43 get a successor that carried on its spirit? What would the new process do for price?

Those questions, and indeed many more, have occupied the thoughts and vocalisations of many a technologist, enthusiast and analyst in the last few months.

It's all of the above that your author seeks to answer in this piece, analysing in depth the new GPUs NVIDIA are launching today. Prepare to say hello to G71 and G73, and the first three SKUs to carry them.

What follows is a fairly in-depth technical discussion of the base architecture common to G71 and G73. Then you'll find talk on G71 and G73 themselves before a look at the reference hardware and an exam of theoretical and gaming performance for those new SKUs.

Hope you enjoy the ride, and please ignore the tech gubbins if it's not your thing. There'll be a summary article following on shortly that'll explain the technology in much easier to understand terms.