Compare any two graphics cards:
Geforce GTX 770 vs Radeon HD 7990
IntroThe Geforce GTX 770 has a GPU core clock speed of 1046 MHz, and the 2048 MB of GDDR5 RAM runs at 1753 MHz through a 256-bit bus. It also is comprised of 1536 SPUs, 128 TAUs, and 32 ROPs.
Compare all of that to the Radeon HD 7990, which comes with a GPU core clock speed of 950 MHz, and 3072 MB of GDDR5 memory set to run at 1500 MHz through a 384-bit bus. It also features 2048 Stream Processors, 128 Texture Address Units, and 32 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
The Radeon HD 7990 should theoretically perform much faster than the Geforce GTX 770 overall. (explain)
Texel RateThe Radeon HD 7990 will be quite a bit (about 82%) faster with regards to texture filtering than the Geforce GTX 770. (explain)
Pixel RateThe Radeon HD 7990 will be much (about 82%) more effective at full screen anti-aliasing than the Geforce GTX 770, and also will be capable of handling higher screen resolutions without losing too much performance. (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: Bandwidth is the maximum amount of data (measured in megabytes per second) that can be transported past the external memory interface in one second. It's worked out by multiplying the interface width by the speed of its memory. If it uses DDR RAM, it should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The better the bandwidth is, the faster the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and higher screen resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that can be applied per second. This number is worked out by multiplying the total number of texture units of the card by the core speed of the chip. The better the texel rate, the better the graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.
Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics card could possibly record to its local memory in one second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of Raster Operations Pipelines by the clock speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate is also dependant on lots of other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to reach the maximum fill rate.