Compare any two graphics cards:
Geforce GTX 670 vs Radeon HD 7990
IntroThe Geforce GTX 670 comes with a GPU core clock speed of 915 MHz, and the 2048 MB of GDDR5 memory is set to run at 1500 MHz through a 256-bit bus. It also is made up of 1344 Stream Processors, 112 TAUs, and 32 Raster Operation Units.
Compare those specs to the Radeon HD 7990, which features a clock speed of 950 MHz and a GDDR5 memory frequency of 1500 MHz. It also features a 384-bit memory bus, and uses a 28 nm design. It is comprised of 2048 SPUs, 128 Texture Address Units, and 32 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Performance-wise, the Radeon HD 7990 should theoretically be quite a bit superior to the Geforce GTX 670 overall. (explain)
Texel RateThe Radeon HD 7990 will be much (more or less 137%) more effective at texture filtering than the Geforce GTX 670. (explain)
Pixel RateThe Radeon HD 7990 should be a lot (more or less 108%) more effective at anti-aliasing than the Geforce GTX 670, and able to handle higher screen resolutions better. (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 information (in units of megabytes per second) that can be transported over the external memory interface in one second. It is worked out by multiplying the bus width by its memory speed. If it uses DDR RAM, it must be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The better the card's memory bandwidth, the faster the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are applied per second. This figure is calculated by multiplying the total amount of texture units by the core clock speed of the chip. The higher the texel rate, the better the graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels per second.
Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics card could possibly record to its local memory in a second - measured in millions of pixels per second. The number is calculated by multiplying the amount of Raster Operations Pipelines by the the core clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel rate also depends 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.