Compare any two graphics cards:
Radeon HD 7870 vs Radeon HD 7970
IntroThe Radeon HD 7870 features a GPU core speed of 1000 MHz, and the 2048 MB of GDDR5 RAM is set to run at 1200 MHz through a 256-bit bus. It also features 1280 Stream Processors, 80 Texture Address Units, and 32 ROPs.
Compare all of that to the Radeon HD 7970, which uses a 28 nm design. AMD has set the core frequency at 925 MHz. The GDDR5 memory is set to run at a frequency of 1375 MHz on this model. It features 2048 SPUs along with 128 TAUs and 32 Rasterization Operator Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
The Radeon HD 7970 should theoretically be much faster than the Radeon HD 7870 overall. (explain)
Texel RateThe Radeon HD 7970 is a lot (more or less 48%) faster with regards to texture filtering than the Radeon HD 7870. (explain)
Pixel RateIf using high levels of AA is important to you, then the Radeon HD 7870 is the winner, though only just barely. (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 information (measured in MB per second) that can be transferred over the external memory interface within a second. It's calculated by multiplying the card's bus width by the speed of its memory. If it uses DDR memory, it should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The better the card's memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and high resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be processed per second. This figure is calculated by multiplying the total amount of texture units of the card by the core clock 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 maximum amount of pixels that the graphics chip could possibly write to its local memory in a second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output rate also depends on quite a few other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to get to the max fill rate.