AMD Radeon HD 7950M vs AMD Radeon HD 7970M Crossfire
AMD Radeon HD 7950M► remove
The AMD Radeon HD 7950M is a DirectX 11 graphics card for large laptops and positioned in the high-end class. It is manufactured in 28nm and based on the GCN (Graphics Core Next) architecture.
The performance should be only slightly below the Radeon HD 7970M as rumors speak from a 3DMark11 performance of P4100 to P4300 points. The GTX 680M scored in first tests P4673 for comparison.
The design of the Radeon 7900M series has its roots to the Pitcairn chip as found, for example, on the desktop Radeon HD 7870. Further details regarding the 7950M in particular are not released yet.
Features of the 7950M include the new UVD3 video decoder for decoding 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 directly from the AMD GPU.
The 7900M 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 7950M can directly support up to 6 connected monitors using Eyefinity Technology if Enduro is disabled.
Other features of the 7900M series include ZeroCore for reducing power consumption when the display is turned off. Power Gating, however, is not supported according to AMD. PowerTune allows automatic overclocking and underclocking of the graphics card as long as the GPU is within its TDP range. 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.
Power consumption of the 7950M should be somewhat below the 7970M and therefore suited for big and heavy DTR-laptops.
AMD Radeon HD 7970M Crossfire► remove
The AMD Radeon HD 7970M Crossfire (or sometimes called the ATI Mobility Radeon HD 7970 X2) is a combination of two high-end graphics card for big and heavy laptops. Usually, each single card renders a single frame. 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 7970M is based on the desktop HD 7870 Pitcairn chip with 1280 1D shaders and 80 texture units. The GCN (graphics core next) architecture supports DirectX11 and OpenGL 4.2. More information on the features of the single 7970M can be found on this page.
The Performance of the two HD 7970M in Crossfire mode is clearly above the GeForce GTX 580M SLI aka. 675M SLI and almost on par with the GeForce GTX 680M SLI. Modern and demanding games like Battlefield 3 are therefore playable in high resolution, max. settings and antialiasing.
The power consumption of the CF combination is very high (2x 100 Watt) and therefore the graphics cards are only suited for very large desktop replacement laptops.
|AMD Radeon HD 7950M||AMD Radeon HD 7970M Crossfire|
|Radeon HD 7900M Series|
|Codename||Wimbledon Pro||Wimbledon XT|
|Cores||1280 - unified||2560 - unified|
|Core||700 MHz||850 MHz|
|Memory||4000 MHz||4800 MHz|
|Bus||256 Bit||2x 256 Bit|
|Max. Memory||2048 MB|
|DirectX||DirectX 11.1, 5.0||DirectX 11.1, 5.0|
|Technology||28 nm||28 nm|
|Features||OpenGL 4.2, OpenCL 1.2|
|212 mm2 Die|