CrossFireX Implementation

While CrossFire had traditionally supported multiple rendering modes like split frame rendering (SFR), and supertiling, for CrossFireX, the focus (at least initially) is solely on alternate frame rendering (AFR). In addition, for right now CrossFireX support is limited to Direct3D applications, OpenGL support will eventually be added in a later driver. We should also mention that 3 and 4-Way CrossFireX support is limited to the Windows Vista OS only; Windows XP isn’t supported (keep in mind that support for NVIDIA’s 3-Way SLI is also exclusive to Vista).

As you can imagine, some games scale better than others with CrossFireX. Right now CrossFireX generally scales better in DX9 apps than DX10. Apparently new features first introduced in DX10 as well as greater usage of persistent resources made the new API more flexible than DX9 for developers, but are now causing headaches for the CrossFireX driver team. The following chart summarizes the scaling AMD’s own labs have seen (we’ll be putting this to the test shortly in our own benchmarks):

As AMD’s driver team has more time to optimize and tweak their graphics driver, expect performance to improve. Also keep in mind when looking at our benchmarks that with up to four GPUs running in tandem, the CPU can become a bottleneck at 1600x1200 depending on the game being tested. In a game based on an older engine like Half-Life 2: Episode Two, we were CPU-bound at 1600x1200 and 1920x1200 in our testing.

Hybrid Graphics

Catalyst 8.3 also includes support for AMD’s Hybrid Graphics technology. Simply pair any AMD 780G (RS780/Radeon HD 3200) motherboard up to a Radeon HD 3450 graphics card for nearly double the performance. Then, when you’re done gaming, you can disable Hybrid Graphics via the control panel to conserve power, or if you’d like, you can connect up to four displays to the system. We’ve included a few Hybrid Graphics benchmarks at the end of this article.

Other improvements

Besides these new features, AMD has added other new features to Catalyst 8.3. Here’s what we’ve been told by AMD:

DirectX 10.1 and Tessellation Support:
ATI Catalyst 8.3 marks the first time DirectX 10.1 support for the ATI Radeon HD 3000 series, and tessellation support for the ATI Radeon HD 3800 series have been made available to developers.

Anti-Aliasing enhancements:
This release of ATI Catalyst introduces anti-aliasing support for all Unreal Engine 3.0 based games (running in DirectX 9 mode). Users can enable Anti-Aliasing for titles such as Gears of War and Unreal Tournament 3 by simply enabling Anti-Aliasing within the ATI Catalyst Control Center. This release of ATI Catalyst allows users to enable the Edge Detect Anti-Aliasing filters while running in the Crossfire Super Anti-Aliasing modes, providing an improved image quality experience.

ATI Catalyst Control Center: HydraVision support for Windows Vista:
This release of ATI Catalyst introduces HydraVision support for the ATI Catalyst Control Center under Windows Vista. HydraVision enables users to more efficiently organize multiple applications across single or multiple displays. High-lights include:

HydraGrid – A new feature found in HydraVision that divides the Windows Vista desktop into user definable areas helping users to more easily move and organize multiple applications.

HydraVision Hotkeys – The ATI Catalyst Control Center Hotkey Manager can be used to quickly setup and define their HydraVision specific hotkey commands

HyrdaVision Virtual desktops – Users can configure up to 9 virtual desktops, enabling users to manage and group multiple applications across user defined desktops. Application positions, desktop associations and display settings can be saved for every virtual desktop

HyrdaVision Wizard – Using the ATI Catalyst Control Center Wizard, users can very quickly configure their HyrdaVision settings.


Digital Panel GPU image scaling:
This release of ATI Catalyst introduces a new setting that allows users to enable GPU accelerated scaling for LCD displays. The new setting “Maintain aspect ratio” improves the display resolution image quality when scaling is enable by maintaining the wide panel aspect ratio (stops the image from looking distorted) on wide aspect LCDs.

ATI Catalyst Control Center: Advanced Video Quality controls:
This release of ATI Catalyst introduces new advanced video quality controls: Edge enhancement, which adjusts the level of sharpness of video content, and noise reduction, which removes ghosting artifacts while preserving details of the original video. The new slider controls can be found in the All Settings page of the Avivo Video tab found in the Catalyst Control Center.