Graphics Cards Guide

NVIDIA GeForce 7800 GTX review

NVIDIA GeForce 7800 GTX (G70)

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8 Vertex Shader Units and 24 Pixel Shader Pipelines

What The GeForce 7800 GTX Brings To The Table

Unlike previous occasions, NVIDIA is only launching one version of their GeForce 7 series initially and that shall be the GeForce 7800 GTX. Previously with the GeForce 5 and 6 series, 'Ultra' was used to classify their highest performing version, but not this time. The new 'GTX' nomenclature according to NVIDIA now signifies their highest performing part. Whether this is true or just an excuse to reserve the 'Ultra' tag if ATI's future R520 part should outdo the GeForce 7800 GTX remains to be seen. NVIDIA has also declined to comment on newer less powerful spin-offs of the GeForce 7800 GTX, but as history has shown, they will follow suit in future and the only two questions would be when and what toned down specs they would feature. Future possibilities aside, the GeForce 7800 GTX is NVIDIA's highest performing GPU now.

For those of you wondering why NVIDIA's internal GPU codenames have now differed from the previous NVxx naming scheme, they figured that the G70 for GeForce 7xxx series is just plain easier to remember. We would agree too, but some hardware aficionados might feel that the first numeral no longer is in tandem with ATI's code names. Well, that's just a side observation, so let's put that away and bring on the main hardware specs:-

8 Vertex Shader Units and 24 Pixel Shader Pipelines

If we were to simplify the G70 architecture in a single line, it's basically an NV40 with internal redesigning to make it more efficient, increased firepower with additional pipelines and a few new features. It might as well be a turbocharged GeForce 6800 Ultra, but the actual performance differential and under the hood changes are vast enough that it warrants a new series by itself. Hence we have the GeForce 7 series, with the 7800 GTX model seated at the very pinnacle.

The GeForce 7800 GTX has 30% more vertex shader units and a 50% increase in shader pipelines from the highest performing GeForce 6 model that had 'only' 6 vertex shader units and 16 pixel shader pipelines. The basic internal structures of each unit remains similar to NV40's vertex and pixel pipeline, but have been re-engineered for higher throughput. We'll touch a little bit more on them on the following page as these are part of the changes that form the new NVIDIA CineFX standard in the G70 architecture. What you can be sure is that the increased processing units and pipelines would greatly contribute to new performance levels for a single graphics card. Perhaps one letdown from the initial rumors were the doubling of the pixel shader pipelines from the GeForce 6800 Ultra, which unfortunately did not come to pass. Nevertheless, with more efficient execution, which increases the throughput of each of the units, we'll soon see just how much advantage the GeForce 7800 GTX maintains ahead of the GeForce 6800 Ultra.

Note that the number of Raster Operation Pipelines (ROPs) still remain at 16 in both the GeForce 7800 GTX and the GeForce 6800 Ultra, but the former supports a new feature and improved antialiasing performance thanks to an updated Intellisample engine. We'll touch on that later to let you in on the improvements.