Compare any two graphics cards:
Radeon HD 5870 vs Radeon HD 7850
IntroThe Radeon HD 5870 features core speeds of 850 MHz on the GPU, and 1200 MHz on the 1024 MB of GDDR5 RAM. It features 1600(320x5) SPUs along with 80 Texture Address Units and 32 ROPs.
Compare that to the Radeon HD 7850, which uses a 28 nm design. AMD has clocked the core frequency at 860 MHz. The GDDR5 RAM works at a speed of 1200 MHz on this model. It features 1024 SPUs as well as 64 TAUs and 32 Rasterization Operator Units.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Both cards have the exact same bandwidth, so in theory they should have the same performance. (explain)
Texel RateThe Radeon HD 5870 should be much (about 24%) more effective at anisotropic filtering than the Radeon HD 7850. (explain)
Pixel RateIf running with a high screen resolution is important to you, then the Radeon HD 7850 is superior to the Radeon HD 5870, but only just. (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 largest amount of information (in units of MB per second) that can be moved over the external memory interface in one second. It is calculated by multiplying the bus width by the speed of its memory. If the card has DDR type memory, the result 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 higher screen 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 higher this number, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in one second.
Pixel Rate: Pixel rate is the maximum number of pixels that the graphics chip can possibly write to the local memory in one second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of Raster Operations Pipelines by the the core clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output rate is also dependant on many other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to reach the max fill rate.