Should be as fast

According to a roadmap we've seen, the RV770XT, the card that ATI might brand as the Radeon HD 4870 512MB will be position to fight the Geforce 9800GTX 512MB.

The RV770XT should be as fast as a non-overclocked version of the Geforce 9800GTX 512MB or around that speed. This means that the RV770XT might be a bit faster or a bit slower than this Nvidia offering.

However, the RV770XT based 512MB cards won't be able to beat overclocked Geforce 9800 GTX 512MB cards, which implies that the RV770XT performance will be a bit below that of an overclocked G92 with 128 Shaders.

This sounds quite good for a card that will sell for $229 at launch.