AMD Radeon HD 6970M Crossfire vs AMD Radeon HD 6990M

AMD Radeon HD 6970M Crossfire

The AMD Mobility Radeon HD 6970M Crossfire (or sometimes called ATI Mobility Radeon HD 6970 X2) is a combination of two high-end graphics card for big and heavy laptops. Usually, each single card renders a single frame (AFR mode). Therefore, it may suffer from micro stuttering in low fps ranges of 30fps. This happens because of different timespans between two frames (e.g., irregular delays between sequential frames).

The HD 6970M is most likely based on the desktop HD 6850 graphics card. The codename of the mobile core is Blackcomb XT and it should have a similar power consumption as the GeForce GTX 480M. According to the roadmap ,the Blackcomb-based chips should feature the UVD3 video processor and Eyefinity+ support.

AMD Radeon HD 6990M

The AMD Mobility Radeon HD 6990M (or sometimes called ATI Mobility Radeon HD 6990) is a high-end graphics card for large laptops (17" and up). It is based on the desktop HD 6870 graphics card and there supports UVD3 decoding and Eyefinity+, albeit with overall reduced clock rates.

The 1120 Stream processors are still based on the "old" 5D architecture similar to the 5000 series. Therefore, the number of shaders is not comparable to the 1D cores of current Nvidia GPUs. The Tessellation performance should be improved (like the desktop 6800 series) with the new cards. The Stream processors can be used with DirectX 11, OpenGL 4.1, DirectCompute 11 and OpenCL. In particular, DirectCompute 11 and OpenCL can both allow the cores to be used for general computations like video transcoding.

The 3D performance should be similar to the Nvidia GeForce GTX 580M in the high end class of notebook graphics cards. Therefore, as of 2011, most modern and demanding games should run in full HD with highest settings fluently. Only Metro 2033 and Crysis (DX11) may need reduced detail settings.

The new UVD3 video decoder supports the decoding of MPEG-4 AVC/H.264, VC-1, MPEG-2, Flash and now also Multi-View Codec (MVC) and MPEG-4 part 2 (DivX, xVid) HD videos on the graphics card.

Furthermore, the HD 6900M series integrates an HD audio controller to transmit HD Audio (TrueHD or DTS Master Audio) over HDMI and DisplayPort (e.g. für Blu-Ray videos).

The AMD HD3D Technology offers support for Blu-Ray 3D and 3D displays (integrated and external). However, the solution is not as mature as Nvidia's 3D Vision.

Thanks to Eyefinity, the graphics chip is able to theoretically drive up to 6 monitors simultaneously. However, this only works if the laptop features enough DisplayPort outputs.

The high power consumption of the chip limits its use only in large laptops with good cooling solutions (e.g. Alienware M18x or Clevo X7200).