Compare any two graphics cards:
Radeon HD 6790 vs Radeon HD 6870
IntroThe Radeon HD 6790 has a core clock speed of 840 MHz and a GDDR5 memory frequency of 1050 MHz. It also uses a 256-bit memory bus, and makes use of a 40 nm design. It is comprised of 800 SPUs, 40 TAUs, and 16 ROPs.
Compare all that to the Radeon HD 6870, which comes with a GPU core clock speed of 900 MHz, and 1024 MB of GDDR5 memory set to run at 1050 MHz through a 256-bit bus. It also is comprised of 1120 SPUs, 56 TAUs, and 32 ROPs.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Both cards have the exact same bandwidth, so theoretically they should have identical performance. (explain)
Texel RateThe Radeon HD 6870 is a lot (more or less 50%) more effective at texture filtering than the Radeon HD 6790. (explain)
Pixel RateThe Radeon HD 6870 will be a lot (about 114%) more effective at FSAA than the Radeon HD 6790, and should be 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: Bandwidth is the max amount of information (measured in megabytes per second) that can be transported past the external memory interface in a second. It's worked out by multiplying the bus width by its memory speed. If the card has DDR RAM, it must be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The higher the bandwidth is, the better the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and higher screen resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that can be processed per second. This number is worked out by multiplying the total amount of texture units of the card by the core clock speed of the chip. The higher this number, the better the video 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 that the graphics card could possibly write to its local memory per second - measured in millions of pixels per second. The figure is calculated by multiplying the amount of 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 rate also depends on many other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the potential to get to the max fill rate.