Compare any two graphics cards:
Radeon HD 4850 512MB vs Radeon R7 250
IntroThe Radeon HD 4850 512MB has a core clock frequency of 625 MHz and a GDDR3 memory frequency of 993 MHz. It also features a 256-bit bus, and uses a 55 nm design. It features 800(160x5) SPUs, 40 Texture Address Units, and 16 Raster Operation Units.
Compare all of that to the Radeon R7 250, which features a clock speed of 1000 MHz and a GDDR5 memory speed of 1150 MHz. It also makes use of a 128-bit bus, and makes use of a 28 nm design. It features 384 SPUs, 24 Texture Address Units, and 8 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Radeon R7 250 will be 16% faster than the Radeon HD 4850 512MB in general, because of its greater bandwidth. (explain)
Texel RateThe Radeon HD 4850 512MB should be a little bit (more or less 4%) more effective at AF than the Radeon R7 250. (explain)
Pixel RateThe Radeon HD 4850 512MB should be much (about 25%) more effective at FSAA than the Radeon R7 250, and will be 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 largest amount of data (in units of MB per second) that can be transferred across the external memory interface within a second. It is calculated by multiplying the interface width by the speed of its memory. In the case of DDR type memory, it should be multiplied by 2 again. If DDR5, multiply by 4 instead. The higher the card's memory bandwidth, the faster the card will be in general. It especially helps with AA, High Dynamic Range and high resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that are processed in one second. This is calculated by multiplying the total texture units of the card by the core 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 processed in a second.
Pixel Rate: Pixel rate is the most pixels the video card could possibly record to the local memory in one second - measured in millions of pixels per second. Pixel rate is worked out 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 filling the screen with pixels (the image). The actual pixel rate also depends on quite a few 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.