Compare any two graphics cards:
GeForce GTX 660 vs Radeon HD 7870
IntroThe GeForce GTX 660 makes use of a 28 nm design. nVidia has set the core speed at 980 MHz. The GDDR5 memory runs at a frequency of 1502 MHz on this specific card. It features 960 SPUs as well as 80 TAUs and 24 Rasterization Operator Units.
Compare those specs to the Radeon HD 7870, which has a GPU core clock speed of 1000 MHz, and 2048 MB of GDDR5 RAM running at 1200 MHz through a 256-bit bus. It also is made up of 1280 Stream Processors, 80 TAUs, and 32 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
The Radeon HD 7870 should in theory be just a bit faster than the GeForce GTX 660 overall. (explain)
Texel RateThe Radeon HD 7870 should be a little bit (approximately 2%) better at texture filtering than the GeForce GTX 660. (explain)
Pixel RateThe Radeon HD 7870 will be a lot (approximately 36%) better at FSAA than the GeForce GTX 660, and capable of handling higher screen resolutions better. (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 (counted in MB per second) that can be transferred across the external memory interface in one second. It is calculated by multiplying the bus width by the speed of its memory. If it uses DDR type RAM, it must be multiplied by 2 again. If it uses 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 amount of texture map elements (texels) that are applied in one second. This is worked out by multiplying the total texture units of the card by the core 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 processed in a second.
Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics card could possibly write to its local memory in one second - measured in millions of pixels per second. The number is worked out by multiplying the amount of Render Output Units by the clock speed of the card. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate also depends on many other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to get to the maximum fill rate.