Compare any two graphics cards:
Geforce GTX 690 vs Radeon HD 7970
IntroThe Geforce GTX 690 has a GPU clock speed of 915 MHz, and the 2048 MB of GDDR5 RAM is set to run at 1502 MHz through a 256-bit bus. It also is comprised of 1536 SPUs, 128 TAUs, and 32 Raster Operation Units.
Compare those specs to the Radeon HD 7970, which has a clock speed of 925 MHz and a GDDR5 memory speed of 1375 MHz. It also makes use of a 384-bit bus, and uses a 28 nm design. It is comprised of 2048 SPUs, 128 TAUs, and 32 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the Geforce GTX 690 is 46% faster than the Radeon HD 7970 overall, due to its higher data rate. (explain)
Texel RateThe Geforce GTX 690 is a lot (more or less 98%) more effective at anisotropic filtering than the Radeon HD 7970. (explain)
Pixel RateIf running with lots of anti-aliasing is important to you, then the Geforce GTX 690 is superior to the Radeon HD 7970, by a large margin. (explain)
Please note that the above 'benchmarks' are all just theoretical - the results were calculated based on the card's specifications, and real-world performance may (and probably will) vary at least a bit.
One or more cards in this comparison are multi-core. This means that their bandwidth, texel and pixel rates are theoretically doubled - this does not mean the card will actually perform twice as fast, but only that it should in theory be able to. Actual game benchmarks will give a more accurate idea of what it's capable of.
Geforce GTX 690
Radeon HD 7970
Memory Bandwidth: Memory bandwidth is the largest amount of data (measured in MB per second) that can be transported across the external memory interface in one second. It's calculated by multiplying the card's bus width by its memory speed. In the case of DDR type RAM, it must be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The better the memory bandwidth, the better the card will be in general. It especially helps with AA, High Dynamic Range and higher screen resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be processed per second. This number is worked out by multiplying the total number of texture units of the card by the core clock speed of the chip. The higher the texel rate, the better the video card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in one second.
Pixel Rate: Pixel rate is the most pixels that the graphics card can possibly record to the local memory per second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the number of Raster Operations Pipelines by the the core clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate also depends on quite a few other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to reach the max fill rate.
Geforce GTX 690
Radeon HD 7970