Compare any two graphics cards:
Geforce GTX 770 vs Radeon HD 7990
IntroThe Geforce GTX 770 comes with a clock speed of 1046 MHz and a GDDR5 memory frequency of 1753 MHz. It also makes use of a 256-bit memory bus, and makes use of a 28 nm design. It features 1536 SPUs, 128 Texture Address Units, and 32 ROPs.
Compare all of that to the Radeon HD 7990, which has a core clock frequency of 950 MHz and a GDDR5 memory speed of 1500 MHz. It also features a 384-bit bus, and uses a 28 nm design. It features 2048 SPUs, 128 Texture Address Units, and 32 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Radeon HD 7990 is 157% quicker than the Geforce GTX 770 in general, due to its greater data rate. (explain)
Texel RateThe Radeon HD 7990 will be quite a bit (more or less 82%) better at texture filtering than the Geforce GTX 770. (explain)
Pixel RateIf running with a high resolution is important to you, then the Radeon HD 7990 is superior to the Geforce GTX 770, by far. (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.
Please note that the price comparisons are based on search keywords - sometimes it might show cards with very similar names that are not exactly the same as the one chosen in the comparison. We do try to filter out the wrong results as best we can, though.
Memory Bandwidth: Memory bandwidth is the largest amount of data (counted in megabytes per second) that can be moved past the external memory interface within a second. The number is worked out by multiplying the card's interface width by its memory clock speed. If the card has DDR type memory, it must be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The higher the memory bandwidth, the faster the card will be in general. It especially helps with AA, HDR and higher screen resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that can be processed in one second. This is calculated by multiplying the total texture units of the card by the core speed of the chip. The better this number, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed per second.
Pixel Rate: Pixel rate is the most pixels that the graphics card can possibly write to the local memory per second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of colour ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate also depends on lots of other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to get to the max fill rate.