Compare any two graphics cards:
Radeon HD 4850 512MB vs Radeon HD 7850
IntroThe Radeon HD 4850 512MB comes with core speeds of 625 MHz on the GPU, and 993 MHz on the 512 MB of GDDR3 memory. It features 800(160x5) SPUs as well as 40 TAUs and 16 ROPs.
Compare those specifications to the Radeon HD 7850, which comes with core clock speeds of 860 MHz on the GPU, and 1200 MHz on the 2048 MB of GDDR5 memory. It features 1024 SPUs along with 64 Texture Address Units and 32 Rasterization Operator Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
The Radeon HD 7850 should in theory perform much faster than the Radeon HD 4850 512MB in general. (explain)
Texel RateThe Radeon HD 7850 will be a lot (approximately 120%) better at anisotropic filtering than the Radeon HD 4850 512MB. (explain)
Pixel RateThe Radeon HD 7850 should be a lot (more or less 175%) better at full screen anti-aliasing than the Radeon HD 4850 512MB, and should be able to handle higher screen resolutions better. (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 max amount of information (measured in MB per second) that can be transported across the external memory interface in a second. It is worked out by multiplying the bus width by its memory clock speed. If the card has DDR memory, it must be multiplied by 2 again. If DDR5, multiply by 4 instead. The better the bandwidth is, the better the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and higher screen resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are processed per second. This is calculated by multiplying the total texture units of the card by the core speed of the chip. The higher the texel rate, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels processed in a second.
Pixel Rate: Pixel rate is the most pixels the video card can possibly record to the local memory in a second - measured in millions of pixels per second. The figure is calculated by multiplying the amount of Render Output Units by the the core clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate also depends on quite a few other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the ability to reach the max fill rate.