Compare any two graphics cards:
Radeon HD 4850 512MB vs Radeon R7 250
IntroThe Radeon HD 4850 512MB features clock 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 that to the Radeon R7 250, which comes with a clock frequency of 1000 MHz and a GDDR5 memory speed of 1150 MHz. It also uses a 128-bit bus, and uses a 28 nm design. It features 384 SPUs, 24 TAUs, and 8 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Performance-wise, the Radeon R7 250 should in theory be a little bit better than the Radeon HD 4850 512MB in general. (explain)
Texel RateThe Radeon HD 4850 512MB is a little bit (about 4%) more effective at texture filtering than the Radeon R7 250. (explain)
Pixel RateThe Radeon HD 4850 512MB will be quite a bit (more or less 25%) faster with regards to FSAA than the Radeon R7 250, and will be able to handle higher resolutions while still performing well. (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 data (counted in megabytes per second) that can be transferred over the external memory interface within a second. It's worked out by multiplying the card's bus width by its memory speed. If it uses DDR type RAM, the result should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The better 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 number of texture map elements (texels) that can be processed per second. This is calculated by multiplying the total amount of texture units of the card by the core clock 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 per second.
Pixel Rate: Pixel rate is the most pixels the graphics card can possibly write to its local memory per second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - aka 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, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.