Compare any two graphics cards:
Radeon HD 3850 512MB vs Radeon HD 4830 512MB
IntroThe Radeon HD 3850 512MB makes use of a 55 nm design. AMD has clocked the core speed at 668 MHz. The GDDR3 RAM is set to run at a speed of 828 MHz on this specific model. It features 320(64x5) SPUs as well as 16 Texture Address Units and 16 Rasterization Operator Units.
Compare those specs to the Radeon HD 4830 512MB, which features a clock speed of 575 MHz and a GDDR3 memory speed of 900 MHz. It also features a 256-bit memory bus, and makes use of a 55 nm design. It is made up of 640(128x5) SPUs, 32 Texture Address Units, and 16 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Radeon HD 4830 512MB will be 9% faster than the Radeon HD 3850 512MB overall, due to its higher bandwidth. (explain)
Texel RateThe Radeon HD 4830 512MB is quite a bit (more or less 72%) faster with regards to AF than the Radeon HD 3850 512MB. (explain)
Pixel RateThe Radeon HD 3850 512MB is just a bit (approximately 16%) faster with regards to FSAA than the Radeon HD 4830 512MB, and also capable of handling higher screen resolutions more effectively. (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 (measured in megabytes per second) that can be transferred across the external memory interface within a second. The number is calculated by multiplying the interface width by its memory clock speed. If it uses DDR type RAM, it should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The better the card's memory bandwidth, the faster 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 amount of texture map elements (texels) that can be applied in one second. This figure is calculated by multiplying the total texture units by the core speed of the chip. The higher the texel rate, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in one second.
Pixel Rate: Pixel rate is the most 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 colour ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel output rate also depends on many other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to get to the maximum fill rate.