Here is a quote from a New game coming out soon on testing:
These results are as clear cut as they can be; the Intel Core 2 Quad QX6700 with all four cores enabled provides the best gameplay experience. We found Supreme Commander playable at 1600x1200 with 16X AF and all in-game settings at their highest levels with quad-core. Anisotropic filtering overall makes little visual quality difference in this game. The only image quality improvements with AF were when we were zoomed all the way in. Some terrain was sharper as you looked toward the top of your screen. However, you do not play this game all the way zoomed in. In this game you are zooming in and out frequently with most of your time is spent zoomed out where AF makes no impact at all. AF does not cause a performance hit however so you can leave it enabled without worrying about it bringing down your framerates.
When we disabled two of the cores and were left with a dual-core CPU we found performance to suffer greatly. We had to lower the resolution to 1280x1204 and lower most quality settings. We had to turn the fidelity down to “medium” which decreased the rendering quality of the entire game. We noticed that the textures looked less detailed, the objects and meshes were less detailed and there was less geometry. We also had to turn off shadow fidelity which meant no shadows were cast from any object or unit. Texture detail and level of detail also had to be decreased to their lowest settings which reduced texture detail further and we experienced less detail as we zoomed out of the map.
The single-core performance was simply dismal and unplayable, period. We have the game set at the absolute lowest settings possible, 1027x768 with everything as low as it will go in the graphics menu of the game, yet, it is still unplayable. 1024x768 is the lowest resolution supported in the game. We are averaging a pitiful 10 FPS. If you look at the graph the single-core performance (red line) is mostly between 5 and 10 FPS, this is entirely unplayable in Supreme Commander.
There are many games planned to be released in the next year that duo and quad cores will be neccesary. Single coes will not hack it. With the edition of SLI and higher fsb speeds it seems the "bottleneck" thing some talk about is gone.
All I am saying is that if you plan to build a new computer, the talk is quad may be the way to go if you plan on having it for a while. Some of us cannot afford to upgrade to a quad processor or build a new computer in 1 to 2 years. Technology will change and in 2 years and a simple upgrade on processor may mean a new motherboard and upgrades in hardware. The developers of the newer games(due out in the next year) are saying the games are performing better with quad cores. There is not much information to look at but it seems they are definitely testing and it looks good. Forget the bottleneck.
The big thing some of the testers are writing up is the cost have gone down so drammatically, it is definitely worth going quad. The tests do show duo cores are 30% faster in current games but the future will tell.
Now I posted the Intel quad info. The AMD quads are getting very nice reviews(AMD fan!)