Compare any two graphics cards:
Radeon HD 4790 vs Radeon HD 6770 1GB
IntroThe Radeon HD 4790 uses a 55 nm design. AMD has set the core speed at 600 MHz. The GDDR5 memory is set to run at a speed of 800 MHz on this particular model. It features 640(128x5) SPUs along with 32 Texture Address Units and 16 ROPs.
Compare those specifications to the Radeon HD 6770 1GB, which features a core clock speed of 900 MHz and a GDDR5 memory speed of 1050 MHz. It also uses a 128-bit memory bus, and uses a 40 nm design. It is comprised of 800 SPUs, 40 Texture Address Units, and 16 Raster Operation Units.
Power Usage and Theoretical Benchmarks
In theory, the Radeon HD 4790 should be 52% quicker than the Radeon HD 6770 1GB in general, due to its greater bandwidth. (explain)
Texel RateThe Radeon HD 6770 1GB should be quite a bit (approximately 88%) better at texture filtering than the Radeon HD 4790. (explain)
Pixel RateIf running with a high resolution is important to you, then the Radeon HD 6770 1GB is the winner, and very much so. (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 maximum amount of data (in units of MB per second) that can be transported past the external memory interface in one second. The number is calculated by multiplying the card's interface width by its memory clock speed. If it uses DDR RAM, the result should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The better the 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 applied in one second. This is calculated by multiplying the total texture units of the card by the core clock speed of the chip. The better the texel rate, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in a 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 number is calculated by multiplying the number of Raster Operations Pipelines by the the card's clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate is also dependant on quite a few other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to reach the max fill rate.