We use Elder Scrolls IV: Oblivion as the ultimate torture test. The only settings we don't maximize are HDR and soft shadows. We disable HDR due to the fact that Nvidia cannot render HDR with antialiasing (ATI cannot either without the "chuck patch") and we disable soft shadows because they don't appear correctly as shadows from the back of a character's head can cast a shadow that can be seen on their face. This can make the women appear to have beards.
In our outdoor scene there are long lines of sight, day is changing into night, and there is foliage swaying in the breeze. This has a severe impact on performance. This is where raw horsepower can muscle its way through this test. That is exactly what the GeForce 7950GX2 can do and chew through. While none of the cards are "playable" (meaning that they average 30 frames per second or more) at anything higher that 1024x768, it demonstrates how well the future of games with many moving objects and techniques could be.
Clearly the Nvidia GeForce 7950GX2 is the winner but for the greater price than the Radeon X1950XTX, the cost is not justified. When we switch to the indoors, the ATI cards beat the Nvidia cards and even the Radeon X1900XT 256 gives the GeForce 7950GX2 some blows.