To test the Nitro's abilities we enrolled a Zotac 9500 GT then thanks to bit-tech's trick we also tried overclocking a Leadtek GTX 280. With the 9500 GT we quickly found we reached the maximum allowed overclocks available using the Nitro, going from the default speeds of 550MHz, 1,600MHz, and 1,625MHz (core, memory, shader) to 731MHz, 2,028MHz, and 1818MHz. This gives us an average increase of 23.8 per cent, which is a figure we saw reflected in our benchmarks where Crysis jumped from 12.7 fps to 16.6 fps. However, using nVidia's overclocking tool in its drivers we found we could actually push the core clock speed further, eventually reaching 771MHz and further increasing our Crysis performance to 16.8 fps.
Next we set to task on the GTX 280 and found there was considerably less overclocking headroom. From starting clock speeds of 602MHz, 2,214MHz, and 1,296MHz we were only able to reach 692MHz, 2,619MHz, and 1,451MHz, or an average increase of 15.1 per cent. This still resulted in a worthwhile boost in performance, though, taking Crysis from 59.9fps 66.6fps.
What does all this tell us? Well, mainly that the 9500 GT is a ridiculously good card in terms of overclocking, whereas the GTX 280 is less so. As for the merits of the Nitro, well it was certainly the most painless overclocking experience I've ever had. However, that's not really the point. This thing costs around £80, which is an amount of money that will almost certainly get you more performance if put towards a faster graphics card in the first place.
The only argument I can see for buying a Nitro is if you already have a top-end card like the GTX 280 and you just want to tweak an extra bit of performance out of it without resorting to things like SLI. Even then, we'd still hope to be spreading the cost over two or three future upgrades, which is assuming it still works with future cards.
The Zotac Nitro makes overclocking your nVidia graphics cards easier than ever before. Unfortunately its ridiculously high price of £80 means most people would be better off spending their money on a better card in the first place.