Compare any two graphics cards:
Radeon HD 4850 512MB vs Radeon HD 7850
IntroThe Radeon HD 4850 512MB features a GPU clock speed of 625 MHz, and the 512 MB of GDDR3 memory is set to run at 993 MHz through a 256-bit bus. It also is comprised of 800(160x5) Stream Processors, 40 TAUs, and 16 Raster Operation Units.
Compare those specifications to the Radeon HD 7850, which comes with core speeds of 860 MHz on the GPU, and 1200 MHz on the 2048 MB of GDDR5 RAM. It features 1024 SPUs along with 64 TAUs and 32 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Radeon HD 7850 is 142% quicker than the Radeon HD 4850 512MB in general, due to its greater bandwidth. (explain)
Texel RateThe Radeon HD 7850 will be a lot (about 120%) more effective at anisotropic filtering than the Radeon HD 4850 512MB. (explain)
Pixel RateIf using lots of anti-aliasing is important to you, then the Radeon HD 7850 is a better choice, 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: Bandwidth is the largest amount of information (measured in MB per second) that can be transported across the external memory interface within a second. It is worked out by multiplying the card's bus width by the speed of its memory. If the card has DDR type memory, the result should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The higher the 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 amount of texture map elements (texels) that can be processed in one second. This number is worked out by multiplying the total amount of texture units of the card by the core speed of the chip. The higher this number, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.
Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics chip could possibly write to its local memory in one second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the number of colour ROPs by the clock speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate is also dependant on quite a few other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the potential to reach the max fill rate.