Compare any two graphics cards:
Radeon HD 7770 vs Radeon R7 250
IntroThe Radeon HD 7770 has a GPU clock speed of 1000 MHz, and the 1024 MB of GDDR5 memory is set to run at 1125 MHz through a 128-bit bus. It also is made up of 640 SPUs, 40 TAUs, and 16 ROPs.
Compare that to the Radeon R7 250, which has 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 is comprised of 384 SPUs, 24 TAUs, and 8 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Radeon R7 250 should be 2% quicker than the Radeon HD 7770 overall, due to its greater bandwidth. (explain)
Texel RateThe Radeon HD 7770 should be a lot (about 67%) faster with regards to AF than the Radeon R7 250. (explain)
Pixel RateThe Radeon HD 7770 should be much (about 100%) faster with regards to AA than the Radeon R7 250, and capable of handling 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 largest amount of data (in units of MB per second) that can be transferred over the external memory interface in a second. It is calculated by multiplying the card's interface width by the speed of its memory. In the case of DDR memory, it should be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The better the memory bandwidth, the better the card will be in general. It especially helps with AA, HDR and high resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that are applied in one second. This figure is worked out by multiplying the total number of 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 in one second.
Pixel Rate: Pixel rate is the most pixels that the graphics card could possibly write to the local memory per second - measured in millions of pixels per second. Pixel rate is calculated by multiplying the amount of ROPs by the the core speed of the card. ROPs (Raster Operations Pipelines - also called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate is also dependant on quite a few other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to reach the maximum fill rate.