Compare any two graphics cards:
Radeon HD 6770 1GB vs Radeon HD 6870
IntroThe Radeon HD 6770 1GB has a core clock frequency of 900 MHz and a GDDR5 memory frequency of 1050 MHz. It also makes use of a 128-bit bus, and uses a 40 nm design. It is comprised of 800 SPUs, 40 Texture Address Units, and 16 ROPs.
Compare those specifications to the Radeon HD 6870, which comes with a GPU core clock speed of 900 MHz, and 1024 MB of GDDR5 RAM running at 1050 MHz through a 256-bit bus. It also is made up of 1120 SPUs, 56 TAUs, and 32 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the Radeon HD 6870 should be a lot faster than the Radeon HD 6770 1GB in general. (explain)
Texel RateThe Radeon HD 6870 should be much (more or less 40%) faster with regards to anisotropic filtering than the Radeon HD 6770 1GB. (explain)
Pixel RateIf using a high screen resolution is important to you, then the Radeon HD 6870 is a better choice, by far. (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 max amount of information (in units of megabytes per second) that can be transported across the external memory interface in a second. It is calculated by multiplying the interface width by its memory speed. If it uses DDR RAM, it must be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The better the 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 amount of texture map elements (texels) that are applied in one second. This number 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 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 number of pixels the video card can possibly write to the local memory per second - measured in millions of pixels per second. The number is worked out by multiplying the number of Raster Operations Pipelines by the clock 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 is also dependant on lots of other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to reach the max fill rate.