Compare any two graphics cards:
Radeon HD 6870 vs Radeon HD 7790
IntroThe Radeon HD 6870 uses a 40 nm design. AMD has clocked the core frequency at 900 MHz. The GDDR5 RAM is set to run at a frequency of 1050 MHz on this model. It features 1120 SPUs as well as 56 Texture Address Units and 32 Rasterization Operator Units.
Compare those specifications to the Radeon HD 7790, which makes use of a 28 nm design. AMD has set the core speed at 1000 MHz. The GDDR5 memory works at a frequency of 1500 MHz on this card. It features 896 SPUs as well as 56 Texture Address Units and 16 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
The Radeon HD 6870 should in theory perform much faster than the Radeon HD 7790 overall. (explain)
Texel RateThe Radeon HD 7790 will be a small bit (approximately 11%) better at AF than the Radeon HD 6870. (explain)
Pixel RateThe Radeon HD 6870 is a lot (about 80%) more effective at full screen anti-aliasing than the Radeon HD 7790, and also will be capable of handling higher screen resolutions more effectively. (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 max amount of data (in units of MB per second) that can be transported across the external memory interface in a second. It is calculated by multiplying the card's bus width by its memory clock speed. If the card has DDR memory, the result should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The better the memory bandwidth, 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 is worked out by multiplying the total amount of texture units by the core clock speed of the chip. The better the texel rate, the better the graphics 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 number of pixels the graphics card can possibly write to its local memory in a second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of Render Output Units by the the core speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate also depends on quite a few other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to reach the max fill rate.