Compare any two graphics cards:
Radeon HD 4830 512MB vs Radeon HD 6770 1GB
IntroThe Radeon HD 4830 512MB features a core clock speed of 575 MHz and a GDDR3 memory speed of 900 MHz. It also uses a 256-bit bus, and makes use of a 55 nm design. It is comprised of 640(128x5) SPUs, 32 TAUs, and 16 ROPs.
Compare those specs to the Radeon HD 6770 1GB, which makes use of a 40 nm design. AMD has clocked the core frequency at 900 MHz. The GDDR5 memory is set to run at a speed of 1050 MHz on this model. It features 800 SPUs as well as 40 TAUs and 16 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Radeon HD 6770 1GB is 17% faster than the Radeon HD 4830 512MB overall, due to its higher bandwidth. (explain)
Texel RateThe Radeon HD 6770 1GB will be quite a bit (approximately 96%) faster with regards to texture filtering than the Radeon HD 4830 512MB. (explain)
Pixel RateIf running with a high resolution is important to you, then the Radeon HD 6770 1GB is superior to the Radeon HD 4830 512MB, by far. (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 data (measured in MB per second) that can be transported past the external memory interface in a second. It's worked out by multiplying the bus width by the speed of its memory. If it uses DDR RAM, it must be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The better the card's memory bandwidth, the better 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 are applied in one second. This is calculated by multiplying the total number of texture units of the card by the core clock speed of the chip. The better 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 maximum amount of pixels the video card could possibly record to the local memory in a 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 drawing the pixels (image) on the screen. The actual pixel output rate also depends on many other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to get to the maximum fill rate.