Compare any two graphics cards:
Radeon HD 4850 1GB vs Radeon HD 6770
IntroThe Radeon HD 4850 1GB features a GPU clock speed of 625 MHz, and the 1024 MB of GDDR4 memory is set to run at 993 MHz through a 256-bit bus. It also is made up of 800(160x5) SPUs, 40 TAUs, and 16 ROPs.
Compare that to the Radeon HD 6770, which has a GPU core clock speed of 900 MHz, and 512 MB of GDDR5 RAM running at 1050 MHz through a 128-bit bus. It also is comprised of 800 SPUs, 40 Texture Address Units, and 16 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically, the Radeon HD 6770 should be a small bit faster than the Radeon HD 4850 1GB in general. (explain)
Texel RateThe Radeon HD 6770 should be a lot (about 44%) faster with regards to AF than the Radeon HD 4850 1GB. (explain)
Pixel RateThe Radeon HD 6770 should be quite a bit (about 44%) faster with regards to full screen anti-aliasing than the Radeon HD 4850 1GB, and should be capable of handling higher resolutions without losing too much performance. (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 information (measured in megabytes per second) that can be transported across the external memory interface within a second. The number is worked out by multiplying the bus width by its memory clock speed. If it uses DDR memory, it should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The higher the memory bandwidth, the faster the card will be in general. It especially helps with AA, HDR and higher screen resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be processed in one second. This is calculated 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 handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied per second.
Pixel Rate: Pixel rate is the most pixels that the graphics chip can possibly write to its local memory per second - measured in millions of pixels per second. The number is worked out by multiplying the amount of colour ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel rate is also dependant on quite a few other factors, especially the memory bandwidth - the lower the bandwidth is, the lower the potential to get to the max fill rate.