Call of Juarez
The GeForce 9600 GT SLI configuration provides a nearly-comfortable level of performance at 1280x1024. On the other hand, the ATI Radeon HD 3870 X2 has an even higher result while occupying only one PCI Express x16 slot and not requiring a CrossFire or SLI compatible mainboard.
The GeForce 9600 GT SLI is slower than the GeForce 8800 GTS or GeForce 9800 GTX at higher resolutions. The SLI tandem doesn’t look like an appealing buy.
Call of Duty 4: Modern Warfare
In this case, the addition of a second GeForce 9600 GT into the system leads to an impressive outcome: at 1920x1200 this subsystem easily beats the GeForce 9800 GTX, let alone the GeForce 8800 GTS 512MB. However, the latter card makes the game playable at 1920x1200 too, but is free from the drawbacks typical of multi-GPU solutions. It’s up to you to decide if the difference in performance is really worth it.