AMD Radeon HD 7970 vs ASUS GeForce GTX 780 DirectCU II OC (GTX780-DC2OC-3GD5)

With many more Raster Operations Pipelines (ROPs) and a bit higher graphics clock speed, the GeForce GTX 780 DirectCU II OC card offers significantly better pixel fill rate. Having higher pixel fillrate allows the GPU to draw more pixels on screen and off screen, which is beneficial for some 3D effects in games, or when playing at higher display resolutions.

The maximum theoretical texture fillrate is dependent on graphics frequency and the number of TMUs (Texture Mapping Units). The ASUS GeForce GTX 780 DirectCU II OC has an edge here, as it runs at higher rate and has many more TMUs. Better texture fill rate allows the graphics card to apply more textures, use more sophisticated 3D effects for each textured picture element, or render 3D image / game environment at higher resolutions without loss of detail.

Single Precision performance illustrates how good the graphics card is at running programs, that process mainly single-precision floating point data. The performance is expressed in GFLOPS, or Giga (billions of) Floating Point Operations Per Second. Since FP calculations are performed by shaders, CUDA cores or stream processors, the performance is directly proportional to their number. It also depends on the processor clock speed. The GeForce GTX 780 DirectCU II OC graphics card 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.

Maximum Double Precision performance is similar to the Single Precision performance, except that it applies to double-precision (64-bit) floating point operations. Games do not use double-precision arithmetics, therefore this characteristic is irrelevant to their performance. The AMD Radeon HD 7970 has a very significant advantage here.

To speed up processing, the cards 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 unit to run at higher screen 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 ASUS GeForce GTX 780 DirectCU II OC offers higher memory clock. Consequently, it has higher memory bandwidth.