Compare any two graphics cards:
Radeon HD 7850 vs Radeon HD 7870
IntroThe Radeon HD 7850 features a clock frequency of 860 MHz and a GDDR5 memory frequency of 1200 MHz. It also uses a 256-bit bus, and makes use of a 28 nm design. It features 1024 SPUs, 64 Texture Address Units, and 32 Raster Operation Units.
Compare that to the Radeon HD 7870, which has clock speeds of 1000 MHz on the GPU, and 1200 MHz on the 2048 MB of GDDR5 RAM. It features 1280 SPUs along with 80 Texture Address Units and 32 Rasterization Operator Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Both cards have the exact same memory bandwidth, so in theory they should have identical performance. (explain)
Texel RateThe Radeon HD 7870 will be a lot (approximately 45%) better at anisotropic filtering than the Radeon HD 7850. (explain)
Pixel RateThe Radeon HD 7870 will be just a bit (about 16%) better at full screen anti-aliasing than the Radeon HD 7850, and will be capable of handling higher resolutions better. (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 (in units of megabytes per second) that can be transported past the external memory interface in one second. It's worked out by multiplying the bus width by its memory clock speed. If it uses DDR memory, it should be multiplied by 2 again. If 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 number of texture map elements (texels) that are applied per second. This figure is calculated by multiplying the total amount of texture units of the card by the core speed of the chip. The higher the texel rate, the better the video card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels per second.
Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics chip could possibly write to its local memory in one second - measured in millions of pixels per second. The figure is worked out by multiplying the amount of Raster Operations Pipelines by the the core clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel fill rate is also dependant on lots of other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to get to the maximum fill rate.