Originally Posted by Goliath.ro
AMD really improved the drivers for ATI cards.
Curently this is my 2nd ATI card, my 1st was during KOTOR 1 game, and back then I had to change drivers every time I wanted to play a different game ( all drivers except one were stuttering heavily in KOTOR, but that driver had big performance problems in other games, so I always had to re-install drivers based on what games I played).
Now I have never had ANY issues with it, the only occasional issues I hear about now is optimization in crossfire, BUT Nvidia also has same issues with new released games so I consider that normal even tho it shouldn't be.
Here is why it sometime buggy and suffer FPS:
If an OpenGL game does not have a CrossFire profile, the Catalyst AI system will set the rendering mode to Scissor by default, with no way to change it to a more suitable or faster mode, such as AFR (More information can be found at the following link
. However, SLI allows the rendering mode to be set for each application manually, even for games which do not have an existing profile.
Setting Catalyst AI to 'Advanced' allows manual mode setting for Direct 3D games, but not OpenGL games, to AFR.
The first generation CrossFire implementations (the Radeon X800 to X1900 series) require an external y-cable/dongle to operate in CrossFire mode due to the PCI-e bus not being able to provide enough bandwidth to run CrossFire without losing a significant amount of performance.
In some cases CrossFire doesn't improve 3D performance – in some extreme cases, it can lower the framerate due to the particulars of an application's coding. This is also true for Nvidia's SLI, as the problem is inherent in multi-GPU systems. This is often witnessed when running an application at low resolutions.
When using CrossFire with AFR, the subjective framerate can often be lower than the framerate reported by benchmarking applications, and may even be poorer than the frame rate of its single-GPU equivalent. This phenomenon is known as micro stuttering and also applies to SLI since it's inherent to multi-GPU configurations.