Compare any two graphics cards:
Radeon HD 6770 1GB vs Radeon HD 6870
IntroThe Radeon HD 6770 1GB features core speeds of 900 MHz on the GPU, and 1050 MHz on the 1024 MB of GDDR5 RAM. It features 800 SPUs as well as 40 Texture Address Units and 16 ROPs.
Compare those specs to the Radeon HD 6870, which uses a 40 nm design. AMD has set the core frequency at 900 MHz. The GDDR5 RAM works at a speed of 1050 MHz on this specific model. It features 1120 SPUs as well as 56 Texture Address Units and 32 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Performance-wise, the Radeon HD 6870 should theoretically be much superior to the Radeon HD 6770 1GB in general. (explain)
Texel RateThe Radeon HD 6870 should be a lot (approximately 40%) more effective at anisotropic filtering than the Radeon HD 6770 1GB. (explain)
Pixel RateThe Radeon HD 6870 is much (more or less 100%) better at AA than the Radeon HD 6770 1GB, and also capable of handling higher screen resolutions while still performing well. (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 max amount of information (counted in MB per second) that can be transported over the external memory interface within a second. The number is calculated by multiplying the bus width by the speed of its memory. If it uses DDR memory, it should be multiplied by 2 again. If DDR5, multiply by 4 instead. The higher the card's memory bandwidth, the better 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 texture map elements (texels) that can be processed per second. This figure is calculated by multiplying the total amount of texture units by the core speed of the chip. The higher the texel rate, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied per second.
Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics card could possibly record to the local memory per second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the number of ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate also depends on quite a few other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the ability to reach the max fill rate.