Compare any two graphics cards:
Radeon HD 5870 vs Radeon HD 6870
IntroThe Radeon HD 5870 has a GPU clock speed of 850 MHz, and the 1024 MB of GDDR5 RAM runs at 1200 MHz through a 256-bit bus. It also is made up of 1600(320x5) SPUs, 80 TAUs, and 32 ROPs.
Compare those specifications to the Radeon HD 6870, which comes with a 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 made up of 1120 SPUs, 56 Texture Address Units, and 32 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the Radeon HD 5870 will be 14% quicker than the Radeon HD 6870 in general, due to its higher bandwidth. (explain)
Texel RateThe Radeon HD 5870 is a lot (more or less 35%) more effective at AF than the Radeon HD 6870. (explain)
Pixel RateThe Radeon HD 6870 will be a small bit (about 6%) faster with regards to FSAA than the Radeon HD 5870, and capable of handling higher resolutions without slowing down too much. (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 (counted in MB per second) that can be transferred past the external memory interface in a second. It's worked out by multiplying the card's bus width by the speed of its memory. If the card has DDR memory, the result should be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The higher the bandwidth is, the faster the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are processed per second. This number is worked out by multiplying the total number of texture units by the core clock 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 per second.
Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics card could possibly write to the local memory in one second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the number of Raster Operations Pipelines by the the core 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 rate is also dependant on many other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to reach the max fill rate.