We are going to be taking a look at quite a few 7800 GT’s over the coming weeks and so to follow on from where Inno3D’s 7800 GT left off, here comes Gainward’s 7800 GT Golden Sample. The Inno3D 7800 GT impressed us with its reasonable price and formidable performance, but today’s 7800 GT from Gainward is a little different, as the Golden Sample moniker has no doubt given away already. Gainward’s card is clocked at 450/1050 and is one of the fastest 7800 GT’s currently on the market.

If you are not aware by now, the 7800 GT clocks differently than most cards. Three cores are controlled by a master clock known as the root clock. The root clock is the one you play with in tools such as Riva Tuner or the Cool-bits registry hack. This subject is covered in more detail on the overclocking page in this review but to sum up, the first core (Vertex) is clock 40 MHz higher than the root clock and the other two cores (Shader and ROP) jump up at a vertex clock oscillation of 27Mhz. What this means is that there are very serious performance sweet spots when overclocking and if you clock below a sweet spot by just a single MHz it can yield a 4 or 5 frame per second deficit. If you’re still confused you can jump straight to the overclocking page for a more detailed explanation.

As already mentioned, the Golden Sample is clocked with a 450 MHz core which is 4 MHz faster than one of these overclocking sweet spots (18 x 27 - 40 = 446). Now, as our last 7800 GT review showed, the good thing about the 7800 series is that we see good performance boosts when they are overclocked,. There were some instances of a 10 fps increase in some benchmarks with reasonable overclocks. What this suggests is that this Gainward at its stock clocks and under warranty will perform much better than the reference 7800 GT and just might be up the rear of the 7800 GTX!

Quick overview of 7800 GT

We already covered this part in the Inno3D 7800 GT review but I thought it best to keep this info in every 7800 review we’ll do from here on.

The main differences between a 7800 GT and GTX are simple. The pipelines are reduced to 20 as opposed to the GTX’s 24, and the clocks speeds change from 430/1200 Mhz to 400/1000 Mhz.

ROPs (render outputs) finalize the rendering process from all of the pixel pipelines, so it’s interesting to note that there are 16, which is the same amount as found in the 6800 Ultra. There is a difference in the amount of vertex shaders between the GT and GTX but GPU’s are not currently vertex limited though this will no doubt change in the 7800 series lifetime with games based on next generation engines such as the Unreal 3 engine. Vertex shaders can do a lot of neat stuff like parallax mapping, and vertex texturing. For the record, parallax mapping is a method for approximating the correct appearance of uneven surfaces by modifying the texture coordinates for each pixel. Parallax is exhibited when areas of a surface appear to move relative to one another as the view position changes. This can be observed on any surface that is not flat. Vertex texturing is a method for fetching data from the texture memory and is useful for techniques like displacement mapping, where the vertex and pixel shaders need to share data with one another.