AMD Radeon HD 6620G + HD 7450M Dual Graphics vs AMD Radeon HD 6480G + HD 7450M Dual Graphics

AMD Radeon HD 6620G + HD 7450M Dual Graphics

The AMD Radeon HD 6620G + HD 7450M Dual Graphics is the combination of a integrated AMD Radeon HD 6620G APU processor graphics card and a dedicated entry level AMD Radeon HD 7450M 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. Currently (June 2011) only DirectX 10 and 11 graphics modes are supported and therefore lower settings and older games are not accelerated. Due to the micro stuttering and performance problems, Dual Graphics may impose more problems than bring performance gains.

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.

AMD Radeon HD 6480G + HD 7450M Dual Graphics

The AMD Radeon HD 6480G + HD 7450M Dual Graphics is a asymmetric Crossfire combination of the Radeon HD 6480G processor graphics card (in Llano APUs) and a dedicated Radeon HD 7450M. The combination was formerly known as Radeon HD 6510G2 (with the Radeon HD 6450M instead of the 7450M which are both based on the same chip).

The Crossfire mode only works for DX10 and DX11 games and may sometimes even decrease performance. In our tests the performance of the combination ranged from a Intel HD Graphics 3000 to a Radeon HD 6490M. Hovever, the combination also suffers from micro stuttering.