After a year of lagging behind rival ATI, Nvidia looks as though it may have finally laid its ghosts to rest. With the launch of the Geforce 6800 Ultra, codenamed NV40, Nvidia has delivered a powerful high-end graphics card.

We were provided with an engineering sample for this preview, and we'll review a resale version as soon as one is made available.

The 6800 Ultra we reviewed runs with a core speed of 400MHz and its 256MB of GDDR3 memory at 550MHz (1.1GHz effectively). These stats might not leap at you, but there's more to a graphics card than pure facts.

The memory is of the new GDDR3 type, which is considerably faster than DDR2. The architecture of the card is far more efficient too. Nvidia can get away with running it at a lower clock speed and still see a strong performance boost over its previous NV3x architecture.

For starters, the 6800 Ultra has 16 pixel pipelines and six vertex shader units. The Superscalar architecture can perform up to eight operations per pixel, which is twice as fast as the previous architecture.

We only had the sample card for a couple of hours, but our tests showed that the 6800 Ultra delivered more than twice the performance of the Geforce FX 5950 Ultra. In particular, the 6800 Ultra excels when running at a high resolution with 4x full scene anti-aliasing (FSAA) turned on, scoring 4,253 in 3DMark 2003.

This is also over twice the performance of any high-end graphics card we have come across.

For the high-end gamer who wants the best-looking visuals, this is one card that can deliver. Needless to say, it does well running at lower resolutions, but doing so is just a waste of power. If you're not going to be running games at 1,600 x 1,200 we?d suggest buying a lower specification card.

However, there are a few downsides to this card. First, it's a double slot card and unsuitable for a lot of small form factor (SFF) cases. Another detractor is its power requirements.

Nvidia is recommending a 480W power supply, which is almost enough to run a small country. SFF cases don't have the power and most towers won't be shipped with such a meaty power supply. This could scupper some of Nvidia's sales.

That said, provided you have the power, the 6800 Ultra is a very powerful card and is the one to beat. It's astonishingly quick and makes light work of any current game.

We'll reserve final judgement until we have pricing and availability, so look out for upcoming issues of PCW for the reviews of retail boards.

Contact: Nvidia
www.nvidia.com

Specifications:

• 400MHz Core
• 550MHz DDR memory (1.1GHz)
• 256MB of GDDR3 Ram
• 16 pixel pipelines
• 6 vertex shaders
• 2 DVI Ports

Also see nVidia launches GeForce 6 story