Compare any two graphics cards:
Radeon HD 4850 512MB vs Radeon HD 7850
IntroThe Radeon HD 4850 512MB comes with clock speeds of 625 MHz on the GPU, and 993 MHz on the 512 MB of GDDR3 RAM. It features 800(160x5) SPUs along with 40 TAUs and 16 ROPs.
Compare that to the Radeon HD 7850, which has a core clock frequency of 860 MHz and a GDDR5 memory frequency of 1200 MHz. It also makes use of a 256-bit bus, and makes use of a 28 nm design. It features 1024 SPUs, 64 Texture Address Units, and 32 ROPs.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
The Radeon HD 7850 should in theory perform quite a bit faster than the Radeon HD 4850 512MB in general. (explain)
Texel RateThe Radeon HD 7850 will be much (more or less 120%) more effective at anisotropic filtering than the Radeon HD 4850 512MB. (explain)
Pixel RateIf running with a high screen resolution is important to you, then the Radeon HD 7850 is superior to the Radeon HD 4850 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: Bandwidth is the max amount of information (counted in MB per second) that can be transferred over the external memory interface in a second. It's worked out by multiplying the card's interface 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 bandwidth is, the better the card will be in general. It especially helps with anti-aliasing, High Dynamic Range and high resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that are applied in one second. This is worked out by multiplying the total amount of texture units by the core speed of the chip. The better the texel rate, the better the 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 the video card can possibly record to the local memory per second - measured in millions of pixels per second. The number is worked out by multiplying the number of ROPs 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 rate also depends on many other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the ability to reach the max fill rate.