Compare any two graphics cards:
Radeon HD 7870 vs Radeon HD 7970
IntroThe Radeon HD 7870 makes use of a 28 nm design. AMD has set the core frequency at 1000 MHz. The GDDR5 memory runs at a speed of 1200 MHz on this specific card. It features 1280 SPUs along with 80 TAUs and 32 ROPs.
Compare that to the Radeon HD 7970, which features core clock speeds of 925 MHz on the GPU, and 1375 MHz on the 3072 MB of GDDR5 memory. It features 2048 SPUs as well as 128 Texture Address Units and 32 Rasterization Operator Units.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Radeon HD 7970 should be quite a bit faster than the Radeon HD 7870 overall. (explain)
Texel RateThe Radeon HD 7970 will be a lot (approximately 48%) better at AF than the Radeon HD 7870. (explain)
Pixel RateThe Radeon HD 7870 should be just a bit (about 8%) better at full screen anti-aliasing than the Radeon HD 7970, and will be able to handle higher resolutions without slowing down too much. (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 (counted in MB per second) that can be transported across the external memory interface in one second. It is calculated by multiplying the bus width by its memory speed. If it uses DDR type RAM, it must be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The better the card's memory bandwidth, 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 amount of texture map elements (texels) that can be processed in one second. This is worked out by multiplying the total amount of texture units by the core speed of the chip. The higher the texel rate, the better the graphics 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 maximum amount of pixels the graphics card can possibly write to its local memory per second - measured in millions of pixels per second. The number is calculated by multiplying the number of ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate also depends on many other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the potential to get to the max fill rate.