Compare any two graphics cards:
Radeon HD 6770 1GB vs Radeon HD 6870
IntroThe Radeon HD 6770 1GB comes with a clock speed of 900 MHz and a GDDR5 memory speed of 1050 MHz. It also features a 128-bit bus, and uses a 40 nm design. It features 800 SPUs, 40 TAUs, and 16 ROPs.
Compare that to the Radeon HD 6870, which comes with a core clock speed of 900 MHz and a GDDR5 memory frequency of 1050 MHz. It also makes use of a 256-bit memory bus, and uses a 40 nm design. It is comprised of 1120 SPUs, 56 TAUs, and 32 Raster Operation Units.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
The Radeon HD 6870 should in theory be a lot faster than the Radeon HD 6770 1GB in general. (explain)
Texel RateThe Radeon HD 6870 will be a lot (about 40%) more effective at AF than the Radeon HD 6770 1GB. (explain)
Pixel RateThe Radeon HD 6870 will be quite a bit (approximately 100%) more effective at AA than the Radeon HD 6770 1GB, and will be able to handle 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 largest amount of data (in units of megabytes per second) that can be transported across the external memory interface within a second. The number is worked out by multiplying the interface width by its memory clock speed. In the case of DDR type RAM, the result should be multiplied by 2 again. If it uses 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 high resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that can be applied in one second. This number is worked out by multiplying the total texture units by the core speed of the chip. The higher this number, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels in one second.
Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics card can possibly write to the local memory in a 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 - also called Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel fill rate is also dependant on lots of other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the potential to reach the max fill rate.