AMD Radeon HD 7550M vs AMD Radeon HD 7500G + HD 7550M Dual Graphics

AMD Radeon HD 7550M

The AMD Radeon HD 7550M (sometimes also called AMD Mobility Radeon HD 7550) is a DirectX11 middle class graphics card for laptops. It is based on the same chip as the Radeon HD 6630M, but only 5 SIMD-engines (= 400 shader) are activated. Furthermore, the memory interface is only 64 bit wide, but supports DDR3 and GDDR5. Depending on the version, the core clocks are between 450 an 550 MHz. The architecture is based on the Northern Islands generation, manufactured in 40nm.

The 400 stream processors should be 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. With the later two the cores can also be used for general computations like transcoding videos.

The 3D performance, limited by the small memory interface, is well below the Radeon HD 6530M. Therefore, current games (2011/2012) will run fluently only in 1024x768 or 1366x768 and low details. Playing highly demanding games like Anno 2070, a further reduction of the settings could be necessary.

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 7500M series integrates a HD audio controller to transmit HD audio (TrueHD or DTS Master Audio) over HDMI and DisplayPort (e.g. for 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 Nvidias 3D Vision.

Thanks to Eyefinity the graphics chip is able to theoretically drive up to 5 monitors simultaneously. However, this only works if the laptop features enough DisplayPort outputs.

The power consumption of the chip should be similar to the Radeon HD 6530M and therefore suited for smaller laptops (13-14").

AMD Radeon HD 7500G + HD 7550M Dual Graphics

The AMD Radeon HD 7500G + HD 7550M Dual Graphics is the combination of a integrated AMD Radeon HD 7500G APU processor graphics card and a dedicated entry level AMD Radeon HD 7550M graphics card in CrossFire combination. It is called AMD Dual Graphics or asymmetric CrossFire and uses AFR (Alternate Frame Rendering) to render different frames on the two graphic cores. Therefore the combination also suffers from micro stuttering (different spaces between two images lead to stuttering altough the framerate is high enough for fluent gaming with only one GPU).

The performance of the Dual Graphics solution depends greatly on the driver support for the used games. In some games the performance may even degrade by 10-15% compared to using only the APU graphics card. In our tests the CrossFire combination was at best about 5-10% faster than the single 7550M. Therefore, due to the micro stuttering and performance problems, Dual Graphics may impose more problems than bring performance gains. Only in best case scenarios a performance similar to the GeForce GT 630M is possible.

The features like PureVideo HD (UVD3) or OpenCL support are similar to the two graphics cards.

As both graphics cards are rendering frames, the power consumption is clearly higher than using only one GPU.