Compare any two graphics cards:
Radeon HD 6870 vs Radeon HD 7850
IntroThe Radeon HD 6870 uses a 40 nm design. AMD has set the core frequency at 900 MHz. The GDDR5 memory works at a frequency of 1050 MHz on this particular model. It features 1120 SPUs as well as 56 TAUs and 32 Rasterization Operator Units.
Compare all that to the Radeon HD 7850, which comes with a clock frequency 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 TAUs, and 32 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
The Radeon HD 7850 should in theory be a little bit faster than the Radeon HD 6870 in general. (explain)
Texel RateThe Radeon HD 7850 is a small bit (more or less 9%) faster with regards to AF than the Radeon HD 6870. (explain)
Pixel RateIf using a high screen resolution is important to you, then the Radeon HD 6870 is the winner, but it probably won't make a huge difference. (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 largest amount of data (in units of megabytes per second) that can be transferred past the external memory interface in one second. It's worked out by multiplying the card's interface width by its memory clock speed. In the case of DDR type 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 high resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are processed per second. This figure is calculated by multiplying the total texture units of the card by the core speed of the chip. The higher this number, the better the graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.
Pixel Rate: Pixel rate is the maximum amount of pixels the video card could possibly record to its local memory in one second - measured in millions of pixels per second. The figure is worked out by multiplying the number of Render Output Units by the the core speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel output rate also depends on many other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the ability to get to the maximum fill rate.