Compare any two graphics cards:
Geforce GTX 680 vs Radeon HD 7870
IntroThe Geforce GTX 680 has a GPU clock speed of 1006 MHz, and the 2048 MB of GDDR5 memory runs at 1502 MHz through a 256-bit bus. It also is made up of 1536 SPUs, 128 Texture Address Units, and 32 ROPs.
Compare those specifications to the Radeon HD 7870, which comes with GPU core speed of 1000 MHz, and 2048 MB of GDDR5 memory set to run at 1200 MHz through a 256-bit bus. It also features 1280 SPUs, 80 TAUs, and 32 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the Geforce GTX 680 will be 25% quicker than the Radeon HD 7870 overall, due to its greater bandwidth. (explain)
Texel RateThe Geforce GTX 680 will be much (approximately 61%) more effective at texture filtering than the Radeon HD 7870. (explain)
Pixel RateThe Geforce GTX 680 will be a small bit (about 1%) better at FSAA than the Radeon HD 7870, and also capable of handling 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 largest amount of data (counted in MB per second) that can be transported past the external memory interface in a second. It's calculated by multiplying the bus width by the speed of its memory. In the case of DDR type memory, it should be multiplied by 2 again. If it uses DDR5, multiply by 4 instead. The better the card's memory bandwidth, the better the card will be in general. It especially helps with anti-aliasing, HDR and high resolutions.
Texel Rate: Texel rate is the maximum amount of texture map elements (texels) that can be processed in one second. This figure is calculated by multiplying the total number of texture units by the core clock speed of the chip. The better this number, the better the graphics 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 maximum number of pixels that the graphics card can possibly record to its local memory per second - measured in millions of pixels per second. The figure is worked out by multiplying the number of Render Output Units by the clock speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate also depends on many other factors, especially the memory bandwidth of the card - the lower the memory bandwidth is, the lower the potential to get to the maximum fill rate.