Compare any two graphics cards:
Radeon HD 7870 XT vs Radeon R9 270X
IntroThe Radeon HD 7870 XT features a clock speed of 925 MHz and a GDDR5 memory speed of 1500 MHz. It also features a 256-bit bus, and uses a 28 nm design. It is comprised of 1536 SPUs, 96 TAUs, and 32 ROPs.
Compare all that to the Radeon R9 270X, which has GPU core speed of 1000 MHz, and 2048 MB of GDDR5 memory set to run at 1400 MHz through a 256-bit bus. It also features 1280 Stream Processors, 80 TAUs, and 32 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
The Radeon HD 7870 XT should theoretically perform a bit faster than the Radeon R9 270X overall. (explain)
Texel RateThe Radeon HD 7870 XT will be a little bit (more or less 11%) more effective at AF than the Radeon R9 270X. (explain)
Pixel RateThe Radeon R9 270X is a little bit (about 8%) better at FSAA than the Radeon HD 7870 XT, and able to handle higher screen 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 information (in units of megabytes per second) that can be transferred across the external memory interface in a second. The number is calculated by multiplying the interface width by its memory clock speed. If it uses DDR RAM, the result 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 anti-aliasing, High Dynamic Range and higher screen resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that are applied per second. This is worked out by multiplying the total texture units by the core clock speed of the chip. The better this number, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels in a second.
Pixel Rate: Pixel rate is the maximum amount of pixels the graphics card can possibly write to its local memory in a second - measured in millions of pixels per second. The figure is calculated by multiplying the amount of Raster Operations Pipelines by the the core clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel fill rate is also dependant on quite a few other factors, most notably the memory bandwidth - the lower the bandwidth is, the lower the ability to get to the max fill rate.