Compare any two graphics cards:
Radeon HD 6870 vs Radeon HD 7790
IntroThe Radeon HD 6870 features a GPU core speed of 900 MHz, and the 1024 MB of GDDR5 RAM runs at 1050 MHz through a 256-bit bus. It also is comprised of 1120 Stream Processors, 56 TAUs, and 32 ROPs.
Compare all of that to the Radeon HD 7790, which features GPU clock speed of 1000 MHz, and 1024 MB of GDDR5 RAM set to run at 1500 MHz through a 128-bit bus. It also features 896 Stream Processors, 56 TAUs, and 16 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically, the Radeon HD 6870 should perform a lot faster than the Radeon HD 7790 overall. (explain)
Texel RateThe Radeon HD 7790 will be a small bit (approximately 11%) faster with regards to AF than the Radeon HD 6870. (explain)
Pixel RateIf running with lots of anti-aliasing is important to you, then the Radeon HD 6870 is the winner, by far. (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 maximum amount of information (in units of MB per second) that can be transferred across the external memory interface within a second. The number is worked out by multiplying the interface width by its memory clock speed. If the card has DDR RAM, it must be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The higher the bandwidth is, the better 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 number of texture map elements (texels) that can be applied in one second. This figure is calculated by multiplying the total number of texture units by the core speed of the chip. The better the texel rate, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in one second.
Pixel Rate: Pixel rate is the maximum number of pixels that the graphics chip can possibly write to its local memory in a second - measured in millions of pixels per second. The figure is calculated by multiplying the amount of ROPs by the the core 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 fill rate is also dependant on quite a few other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.