While AMD seems to be concentrating on making the mainstream market its own, Nvidia has continued to hang onto its crown as king of the hill when it comes to outright performance. Cementing that place even further is the company's latest hi-end GPU, the GTX280.

The GT200 upon which it's based is the company's second generation DX10 core and is more an evolution of the highly successful G92 GPU - which was seen by many to be a die shrink of the even more successful G80 - than a new design from the ground up.

But by revamping the good parts of the previous architecture and redesigning the less good bits, Nvidia has managed to double the processing power of the GT200 over its siblings. Presently there are just two flavours of the GT200; the GXT260 and the flagship GTX280, the GPU that our review Zotac card is based on.

But it's some evolution: the GT200 is a huge chip. Currently the largest chip that Nvidia has produced at 576mm², the 65nm process core contains 1.4 billion transistors. That's some jump from the 690 million of the G80 or the 754 million of the G93.

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The GTX280 has 240 Stream Processors, again a significant jump over its siblings (the GTX260 has just 192) which are clocked at 1,296MHz. The core itself is clocked at 602MHz while the 1GB of GDDR3 running through a 512-bit memory interface is clocked at 1,107MHz (2.2GHz effective), all of which gives the GTX280 a very impressive memory bandwidth of 141.7GB/sec, twice that of the standard 9800GTX.

To keep this monster cool there is a dual-slot heat-sink and cooler which just about covers the entire PCB. Nvidia's maximum power rating for the GTX280 is 236W, and to this end there are single 6-pin and 8-pin power connectors. It makes for a substantial card and at 26.6cm in length it may not fit in many smaller cases. If you have the space and wallet for it, the GTX280 also supports triple SLI.

The GPU is now so powerful that Nvidia is pushing out the idea of ‘parallel processing' where the graphics core is used for more than just games; video encoding, folding and high-end computing are a few of the ideas being banded about.

Zotac may be a new name to most; quite understandable as they have only been in existence since 2006, but in that short time have already got themselves into the position of being one of Nvidia's biggest board partners. They have two card ranges that will interest the enthusiast; Zone for passive and quiet cards, and the range that our review sample came from - AMP - which is the overclocking range.

From the outside the AMP Edition GTX280 looks just like the reference design with a fetching Zotac label on the cooler. But it's under the heat-sink that things get a little more interesting.

The core clock runs at 700MHz, 68MHz over the reference speed, while both the shader and memory clocks have been played with too. The shader clock runs at 1,400MHz and the memory is clocked a shade under 50MHz faster at 1,15GHz (2.3GHz effective).

Performance-wise, as you can imagine, the GTX280 AMP is no slouch and quite frankly it is a waste of time testing a card like this at 1,024 x 768 resolution as the card isn't being pushed. So we tested instead at 1,600 x 1,200 resolution to try to stress it a little.

Testing with 3Dmark06 produced a score of 16,088, while testing the DX9 version of Company of Heroes at 1,600 by 1,200 with 4x Anti Aliasing and 4x Antroscopic filtering and all game details set to high it gave an outstanding maximum frame rate of 330fps. Even that modern killer of graphics cards, Crysis, failed to really stop it: with all gaming details set to high and the same 1600 x 1200 resolution and 4x Anti-Aliasing, it produced a respectable 51.6fps, one of the highest we have seen at that resolution.

Bundled in the box you get a driver CD and a full copy of the Racedriver Grid game, while the hardware bundle consists of DVI and HDMI adaptors, video out adaptor, two Molex to PCI-E power adaptors (one 6-pin, one 8-pin) and a S/PDIF audio cable.

Nvidia's performance crown is still intact with the GTX280, but it's not a cheap option. Zotac's overclocked GTX280 is the fastest single core card we have tested to date, but you'll need a fully laden wallet to enjoy it.