Compare any two graphics cards:
Radeon HD 6790 vs Radeon HD 7770
IntroThe Radeon HD 6790 makes use of a 40 nm design. AMD has set the core frequency at 840 MHz. The GDDR5 memory works at a speed of 1050 MHz on this model. It features 800 SPUs as well as 40 Texture Address Units and 16 Rasterization Operator Units.
Compare all that to the Radeon HD 7770, which features a core clock frequency of 1000 MHz and a GDDR5 memory speed of 1125 MHz. It also features a 128-bit memory bus, and makes use of a 28 nm design. It is comprised of 640 SPUs, 40 Texture Address Units, and 16 Raster Operation Units.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
In theory, the Radeon HD 6790 is 87% quicker than the Radeon HD 7770 in general, because of its higher data rate. (explain)
Texel RateThe Radeon HD 7770 is a little bit (more or less 19%) faster with regards to texture filtering than the Radeon HD 6790. (explain)
Pixel RateThe Radeon HD 7770 should be a bit (about 19%) faster with regards to FSAA than the Radeon HD 6790, and capable of handling higher resolutions better. (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 largest amount of information (measured in megabytes per second) that can be transported past the external memory interface within a second. It is worked out by multiplying the card's bus width by its memory speed. If the card has DDR type memory, it should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The better the bandwidth is, the faster the card will be in general. It especially helps with AA, High Dynamic Range and high resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be processed per second. This figure is calculated by multiplying the total number of texture units of the card by the core clock speed of the chip. The higher the texel rate, the better the card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.
Pixel Rate: Pixel rate is the maximum number of pixels 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 amount of Render Output Units by the the core clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate also depends on many other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to reach the maximum fill rate.