Ran in single card mode there is not a title out that can daunt the 7800GT, except perhaps Fear, which puts a strain on the entire system and by default, only allows resolutions of 1024X768. The XFX 7800GT was playable with all features turned to high, but occasionally hiccupped here and there throughout the game.
All the other games I played were playable at 1280X1024 and showed no signs of instability or hiccups even with all the advanced features enabled. RTS games really are not all that graphic intensive and some games like AOE 3 or Rome Total War actually need hefty CPU power to play well due to the fact that there are so many different things on the screen for the CPU to mathematically calculate.
FPS shooters usually push the curve when it comes to using the latest technology, games like Far Cry and Half-Life 2 really upped the ante on graphics and helped usher in the Direct-X 9 era and now Fear comes along to take things just a bit further. Using two cards in an SLI configuration can play any game with everything turned to maximum and not show any signs of frame drops or hiccups. Games can be seen at resolutions up to 1680X1024 and still be completely playable with things set to max. The games look incredible even at 1280X1024 as shown in gaming screenshots below. All the pics are shown at the factory default settings on the cards control panel with the in-game setting at maximum and at a 1280X1024 resolution with a refresh rate of 75MHz.