ATI Radeon HD 6870 vs HIS Radeon HD 5870 DiRT 2 Edition (H587F1GDG)

Since two cards have the same number of ROPs and the ATI Radeon HD 6870 graphics unit has higher operating frequency, its pixel fillrate is higher. Better maximum pixel fill rate means that the card can draw more pixels on and off screen each second, increasing overall performance, unless there are bottlenecks somewhere else.

Even though it has lower graphics clock, the Radeon HD 5870 DiRT 2 Edition comes with more TMUs (Texture Mapping Units), which results in higher texture fill rate. Better texture fill rate means that the graphics card can apply more textures and/or utilize more complex 3D effects for each textured picture element, which improves visual appearance of games and generated images.

Single Precision performance illustrates how many single-precision floating point operations the graphics card can execute per second. The performance is expressed in billions of Floating Point Operations Per Second, or GFLOPS. All single-precision calculations are performed by stream processors or CUDA cores, therefore the more cores / processors the graphics card has the better. Performance also depends on the processor clock speed. The Radeon HD 5870 DiRT 2 Edition is 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.

Memory bandwidth parameter specifies how much memory (in Gigabytes) the graphics unit can read from or write to dedicated memory per second. Graphics cards with higher memory bandwidth have better performance at high display resolutions, or when using large and detailed textures, and/or utilizing complex 3D effects and filters, like anti-aliasing. The bandwidth is dependent on memory type, speed, and width of memory interface. Specifically, the HIS Radeon HD 5870 DiRT 2 Edition graphics card offers higher memory clock. Consequently, it has more memory bandwidth.