AMD Radeon HD 8650M vs AMD Radeon HD 8650G + HD 8670M Dual Graphics

AMD Radeon HD 8650M

The AMD Radeon HD 8650M is a DirectX 11.1 graphics card for laptops. Just like the 8500M and 8700M series, it is based on the Mars chip (28nm GCN architecture) with 384 shader cores, 24 TMUs, and 8 ROPs. The core is clocked at 650 MHz (700 MHz Boost) and can access a fast GDDR5 RAM (64 Bit, 4500 MHz).

The performance of the Radeon HD 8650M should be in range of the Radeon HD 8730M or GeForce GT 640M LE. Due to the fast GDDR5 memory, the 8650M should even beat the DDR3-equipped HD 8670M. Current and demanding games like Far Cry 3 will run fluently only in low resolutions and detail settings.

The 384 shaders can be used with OpenCL 1.2 for general-purpose calculations (as 6 compute units). Compared to old TeraScale 2 chips, the GCN-based Mars architecture offers improved performance in this framework.

Features of the 8650M include video decoding via UVD3 for decoding MPEG-4 AVC/H.264, VC-1, MPEG-2, and Flash directly from the AMD GPU. Multi-View Codec (MVC) and MPEG-4 part 2 (DivX, xVid) HD videos are now compatible as well.

The 8600M series also supports automatic graphics switching between the integrated GPU and discrete GPU. Called Enduro, the technology supersedes AMD's Dynamic Switchable Graphics and is similar to Nvidia's Optimus. Furthermore, the 8670M can directly support up to 2 connected monitors using Eyefinity Technology if Enduro is disabled.

Other features of the 8600M series include ZeroCore for reducing power consumption when the display is turned off and Power Gating to power down areas of the chip that are not used. PowerTune allows automatic overclocking and underclocking of the graphics card as long as the GPU is within its TDP limit. For example, the chip may be underclocked when running FurMark and OCCT, but will overclock in certain games like Lost Planet, Crysis or Resident Evil 5.

The integrated HD audio processor is able to transmit HD Audio (TrueHD or DTS Master Audio) over HDMI and DisplayPort (e.g., for Blu-Ray videos). Additionally, it now allows audio to output simultaneously and in parallel to multiple devices with the new Discrete Digital Multipoint Audio (DDMA) feature.

The power consumption should be clearly below that of the old HD 7670M. As a result, the 8650M is suited for 13-inch notebooks or larger.

AMD Radeon HD 8650G + HD 8670M Dual Graphics

The AMD Radeon HD 8650G + HD 8670M Dual Graphics is the combination of an integrated AMD Radeon HD 8650G APU processor graphics card and a dedicated entry level AMD Radeon HD 8670M 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 slightly compared to using only the dedicated graphics card. Only in best case scenarios the performance of a GT 640M is possible. Therefore, 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.