Compare any two graphics cards:
Radeon HD 7870 vs Radeon R9 270
IntroThe Radeon HD 7870 features a GPU core clock speed of 1000 MHz, and the 2048 MB of GDDR5 RAM runs at 1200 MHz through a 256-bit bus. It also is comprised of 1280 Stream Processors, 80 TAUs, and 32 ROPs.
Compare that to the Radeon R9 270, which comes with GPU clock speed of 900 MHz, and 2048 MB of GDDR5 RAM set to run at 1400 MHz through a 256-bit bus. It also is comprised of 1280 SPUs, 80 Texture Address Units, and 32 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Performance-wise, the Radeon R9 270 should in theory be a bit better than the Radeon HD 7870 in general. (explain)
Texel RateThe Radeon HD 7870 is a small bit (more or less 11%) more effective at anisotropic filtering than the Radeon R9 270. (explain)
Pixel RateIf using lots of anti-aliasing is important to you, then the Radeon HD 7870 is the winner, but it probably won't make a huge difference. (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 maximum amount of data (counted in MB per second) that can be moved across the external memory interface in a second. It's calculated by multiplying the card's bus width by its memory clock speed. In the case of DDR RAM, the result should be multiplied by 2 once again. If DDR5, multiply by 4 instead. The higher the memory bandwidth, the better the card will be in general. It especially helps with AA, High Dynamic Range and higher screen resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that can be processed in one second. This figure is worked out by multiplying the total number of texture units of the card by the core clock 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 graphics card can possibly write to the local memory per second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of Raster Operations Pipelines by the the core speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate also depends on many other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to get to the maximum fill rate.