Compare any two graphics cards:
Radeon HD 7850 vs Radeon HD 7870
IntroThe Radeon HD 7850 comes with a core clock speed of 860 MHz and a GDDR5 memory frequency of 1200 MHz. It also features a 256-bit bus, and makes use of a 28 nm design. It features 1024 SPUs, 64 Texture Address Units, and 32 ROPs.
Compare those specs to the Radeon HD 7870, which has a clock speed of 1000 MHz and a GDDR5 memory frequency of 1200 MHz. It also features a 256-bit memory bus, and makes use of a 28 nm design. It is made up of 1280 SPUs, 80 TAUs, and 32 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Both cards have the exact same memory bandwidth, so in theory they should perform the same. (explain)
Texel RateThe Radeon HD 7870 should be a lot (more or less 45%) faster with regards to texture filtering than the Radeon HD 7850. (explain)
Pixel RateThe Radeon HD 7870 will be just a bit (approximately 16%) faster with regards to AA than the Radeon HD 7850, and also should be capable of handling higher screen resolutions without losing too much performance. (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 moved over the external memory interface within a second. The number is worked out by multiplying the interface width by its memory speed. In the case of DDR memory, it should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The better the card's memory bandwidth, the faster 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 texture map elements (texels) that are processed 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 video 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 amount of pixels the video card can possibly record to its local memory in one second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the number of colour ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate also depends on lots of other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to reach the max fill rate.