Compare any two graphics cards:
Radeon HD 7850 vs Radeon HD 7870
IntroThe Radeon HD 7850 makes use of a 28 nm design. AMD has set the core frequency at 860 MHz. The GDDR5 RAM is set to run at a frequency of 1200 MHz on this card. It features 1024 SPUs as well as 64 TAUs and 32 ROPs.
Compare all that to the Radeon HD 7870, which features a core clock frequency of 1000 MHz and a GDDR5 memory speed of 1200 MHz. It also makes use of a 256-bit bus, and uses a 28 nm design. It is comprised 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 the exact same memory bandwidth, so theoretically they should have the same performance. (explain)
Texel RateThe Radeon HD 7870 is much (about 45%) better at AF than the Radeon HD 7850. (explain)
Pixel RateThe Radeon HD 7870 should be just a bit (about 16%) better at full screen anti-aliasing than the Radeon HD 7850, and also capable of handling higher 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 maximum amount of information (in units of megabytes per second) that can be transported across the external memory interface in one second. It's calculated by multiplying the card's bus width by its memory clock speed. If the card has DDR RAM, it 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, HDR and high resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that are applied per second. This number is calculated by multiplying the total texture units of the card by the core speed of the chip. The better this number, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels in one second.
Pixel Rate: Pixel rate is the maximum number of pixels that the graphics chip could possibly write to its local memory per second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of Render Output Units by the the card's clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output rate also depends on quite a few other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to reach the maximum fill rate.