AMD Radeon HD 7870 GHz Edition vs HD 8760 (OEM)

There are two characteristics that affect the maximum theoretical pixel fillrate. These are graphics clock rate and the number of ROPs. The AMD Radeon HD 7870 GHz Edition has an edge here, as it has twice as many Raster Operations Pipelines, and both graphics cards operate at the same frequency. Better maximum pixel fill rate allows more pixels to be drawn on screen per second, which results in increased performance, unless the graphics card is limited by something else, such as texture mapping or memory bandwidth.

Graphics card performance in modern games is less dependent on pixel fillrate, and more on texture fill rate. This parameter is proportional to the number of TMUs and graphics clock speed. With graphics frequency being identical between two graphics cards, the AMD Radeon HD 7870 GHz Edition has twice as many Texture Mapping Units (TMUs), as a result its texture fillrate is significantly higher. Better maximum texture fill rate means that the graphics card can apply more textures and/or use more sophisticated 3D effects for each texel, which improves visual appearance of games and generated images.

Single Precision performance, measured in GFLOPS or billions of Floating Point Operations Per Second, shows how fast the GPU is at executing applications, that utilize single-precision floating point numbers. All single-precision calculations are performed by CUDA cores or stream processors, as such the more cores / processors the graphics unit has the better. Performance also depends on the processor clock rate. The AMD Radeon HD 7870 GHz Edition graphics card is considerably faster here. Higher single-precision performance number means the GPU will perform better in general computing applications. Since CUDA cores or stream processors are also used as vertex and geometry shaders for 3D image generation, higher performance is also beneficial to games.

Maximum Double Precision performance is similar to the Single Precision performance, except that it applies to double-precision (64-bit) floating point operations. This characteristic is unrelated to games performance because games do not use double-precision arithmetics. The AMD Radeon HD 7870 GHz Edition has an upper hand here.

To speed up processing, the GPUs store 3D scene data, textures and intermediate data, used for image generation, in on-board memory. The video memory usually has much higher bandwidth than system RAM, and more bandwidth allows the graphics card to run at higher display resolutions, use larger and more detailed textures, and apply more complex 3D effects and filters. The bandwidth is dependent on memory type, speed, and memory interface width. Specifically, higher memory bandwidth of the AMD Radeon HD 7870 GHz Edition GPU is a direct result of higher memory clock and wider bus.