Compare any two graphics cards:
Radeon HD 7790 vs Radeon HD 7850
IntroThe Radeon HD 7790 comes with a clock speed of 1000 MHz and a GDDR5 memory frequency of 1500 MHz. It also uses a 128-bit memory bus, and makes use of a 28 nm design. It is made up of 896 SPUs, 56 TAUs, and 16 Raster Operation Units.
Compare that to the Radeon HD 7850, which comes with a GPU core clock speed of 860 MHz, and 2048 MB of GDDR5 RAM set to run at 1200 MHz through a 256-bit bus. It also is comprised of 1024 SPUs, 64 Texture Address Units, and 32 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the Radeon HD 7850 should be 60% faster than the Radeon HD 7790 overall, due to its higher bandwidth. (explain)
Texel RateThe Radeon HD 7790 should be a little bit (approximately 2%) faster with regards to AF than the Radeon HD 7850. (explain)
Pixel RateIf using lots of anti-aliasing is important to you, then the Radeon HD 7850 is superior to the Radeon HD 7790, by a large margin. (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 maximum amount of data (counted in megabytes per second) that can be transferred across the external memory interface within a second. It's worked out by multiplying the card's interface width by the speed of its memory. If the card has DDR memory, it must be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The higher the bandwidth is, the better the card will be in general. It especially helps with AA, High Dynamic Range and higher screen resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be applied per second. This is worked out by multiplying the total amount of texture units of the card by the core 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 in one second.
Pixel Rate: Pixel rate is the most pixels the video card can possibly record to its local memory in one second - measured in millions of pixels per second. The number is worked out by multiplying the number of Raster Operations Pipelines by the clock speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel rate also depends on quite a few other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the ability to get to the max fill rate.