Compare any two graphics cards:
Radeon HD 7790 vs Radeon HD 7850
IntroThe Radeon HD 7790 comes with a clock frequency of 1000 MHz and a GDDR5 memory frequency of 1500 MHz. It also features a 128-bit bus, and uses a 28 nm design. It is made up of 896 SPUs, 56 Texture Address Units, and 16 ROPs.
Compare that to the Radeon HD 7850, which features a clock speed of 860 MHz and a GDDR5 memory frequency of 1200 MHz. It also features a 256-bit memory bus, and uses a 28 nm design. It is comprised of 1024 SPUs, 64 TAUs, and 32 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Radeon HD 7850 should be 60% quicker than the Radeon HD 7790 in general, because of its greater bandwidth. (explain)
Texel RateThe Radeon HD 7790 will be just a bit (more or less 2%) better at texture filtering than the Radeon HD 7850. (explain)
Pixel RateThe Radeon HD 7850 should be much (approximately 72%) better at full screen anti-aliasing than the Radeon HD 7790, and should 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.
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 largest amount of data (measured in megabytes per second) that can be moved over the external memory interface within a second. It's worked out by multiplying the card's interface width by its memory speed. If the card has DDR memory, the result should be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The better the memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, HDR and high resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that are applied in one second. This is calculated by multiplying the total texture units by the core clock speed of the chip. The better 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 the video card can possibly write to the local memory in one second - measured in millions of pixels per second. The number is worked out by multiplying the number of ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate also depends on quite a few other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the potential to get to the max fill rate.