The Rolls-Royce of graphic cards by NVidia

Not a week passes without a new graphic card coming out to match the competitor's. The latest top end one from NVidia is called Geforce 7800 GTX 512. And this '512 MB' mention is what actually puts this card apart from the other GTXs.
The GPU's speed has jumped from 430 to 550 MHz and the RAM from 600 to 850 MB. In practice, it is 20 to 30 % faster than a GTX 256.
This card allows NVidia to take back the upper hand over ATI in the top end range.
Unfortunately, it is quite unlikely that the Geforce 7800 GTX 512 will ever be available as a custom feature for the new G5. The reason is Apple certainly won't want to jeopardise the sales of the Quadro FX 4500, which is twice as expensive, less powerful, and designed to give its best for a handful of software only.