Compare any two graphics cards:
Radeon HD 7850 vs Radeon HD 7870
IntroThe Radeon HD 7850 uses a 28 nm design. AMD has set the core frequency at 860 MHz. The GDDR5 memory runs at a speed of 1200 MHz on this model. It features 1024 SPUs along with 64 Texture Address Units and 32 ROPs.
Compare all that to the Radeon HD 7870, which features a clock frequency of 1000 MHz and a GDDR5 memory frequency of 1200 MHz. It also makes use of 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.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Both cards have exactly the same bandwidth, so in theory they should have identical performance. (explain)
Texel RateThe Radeon HD 7870 will be much (about 45%) more effective at texture filtering than the Radeon HD 7850. (explain)
Pixel RateThe Radeon HD 7870 will be a small bit (about 16%) more effective at AA than the Radeon HD 7850, and also should be capable of handling higher screen resolutions more effectively. (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 data (in units of MB per second) that can be moved past the external memory interface in a second. The number is worked out by multiplying the bus width by the speed of its memory. If it uses DDR memory, it should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The better the card's memory bandwidth, the better the card will be in general. It especially helps with AA, HDR and high resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that can be applied per second. This number is worked out by multiplying the total amount of texture units of the card by the core clock speed of the chip. The higher the texel rate, the better the graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in a second.
Pixel Rate: Pixel rate is the maximum amount of pixels the graphics card could possibly write to its local memory in one second - measured in millions of pixels per second. The number 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 rate is also dependant on lots of other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to reach the max fill rate.