Compare any two graphics cards:
Radeon HD 6790 vs Radeon HD 7790
IntroThe Radeon HD 6790 comes with a GPU core clock speed of 840 MHz, and the 1024 MB of GDDR5 memory runs at 1050 MHz through a 256-bit bus. It also features 800 SPUs, 40 Texture Address Units, and 16 Raster Operation Units.
Compare that to the Radeon HD 7790, which features a core clock frequency of 1000 MHz and a GDDR5 memory speed of 1500 MHz. It also uses a 128-bit bus, and uses a 28 nm design. It is comprised of 896 SPUs, 56 Texture Address Units, and 16 Raster Operation Units.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically, the Radeon HD 6790 should be much faster than the Radeon HD 7790 overall. (explain)
Texel RateThe Radeon HD 7790 should be quite a bit (approximately 67%) better at texture filtering than the Radeon HD 6790. (explain)
Pixel RateThe Radeon HD 7790 is just a bit (about 19%) faster with regards to full screen anti-aliasing than the Radeon HD 6790, and should be 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.
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 MB per second) that can be moved across the external memory interface in one second. It's worked out by multiplying the bus width by its memory speed. In the case of 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, HDR and high resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are applied in one second. This number is worked out by multiplying the total texture units of the card by the core clock speed of the chip. The better this number, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed per second.
Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics card can possibly write to the 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 card's clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for outputting the pixels (image) to the screen. 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 reach the max fill rate.