HIS Radeon HD 6790 Fan DiRT3 Edition vs NVIDIA GeForce GTX 550 Ti

Even though it has lower graphics clock rate, the HIS Radeon HD 6790 Fan DiRT3 Edition comes with higher pixel fill rate, thanks to more ROPs (Raster Operations Pipelines). Better pixel fill rate means that the graphics card can draw more pixels on and off screen each second, increasing overall performance, unless there are bottlenecks in other areas, such as texture fillrate, CPU speed or memory bandwidth.

Even so its graphics clock rate is slower, the Radeon HD 6790 Fan DiRT3 Edition GPU has more TMUs, which results in higher texture fill rate. Better texture fill rate means that the card can utilize more sophisticated 3D effects and/or map more textures to each texel, which improves games visual appearance.

Maximum Single Precision performance, measured in GFLOPS or billions of Floating Point Operations Per Second, illustrates how fast the graphics unit is at running programs, that use 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 card has the better. Performance also depends on the processor clock rate. The HIS Radeon HD 6790 Fan DiRT3 Edition graphics card is substantially faster here. Higher single-precision performance number means the graphics card will perform better in general computing applications. Since stream processors or CUDA cores are also used as vertex and geometry shaders for 3D image generation, higher performance is also beneficial to games.

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 width of memory interface. Specifically, the Radeon HD 6790 Fan DiRT3 Edition comes with higher clocked memory and wider bus. As such, it has higher memory bandwidth.