Compare any two graphics cards:
GeForce GTX 580 vs Radeon HD 7870
IntroThe GeForce GTX 580 features a GPU core clock speed of 772 MHz, and the 1536 MB of GDDR5 RAM is set to run at 1002 MHz through a 384-bit bus. It also features 512 SPUs, 64 Texture Address Units, and 48 ROPs.
Compare that to the Radeon HD 7870, which features clock speeds of 1000 MHz on the GPU, and 1200 MHz on the 2048 MB of GDDR5 memory. It features 1280 SPUs as well as 80 TAUs and 32 Rasterization Operator Units.
(No game benchmarks for this combination yet.)
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
The GeForce GTX 580, in theory, should perform quite a bit faster than the Radeon HD 7870 in general. (explain)
Texel RateThe Radeon HD 7870 is quite a bit (approximately 62%) faster with regards to anisotropic filtering than the GeForce GTX 580. (explain)
Pixel RateThe GeForce GTX 580 should be a little bit (about 16%) better at AA than the Radeon HD 7870, and also should be capable of handling higher screen resolutions without losing too much performance. (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: Bandwidth is the largest amount of data (in units of megabytes per second) that can be transported over the external memory interface in a second. It is worked out by multiplying the interface width by its memory clock speed. If it uses DDR type RAM, it must be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The better the bandwidth is, the better the card will be in general. It especially helps with anti-aliasing, HDR and higher screen resolutions.
Texel Rate: Texel rate is the maximum number of texture map elements (texels) that can be processed per second. This number is worked out by multiplying the total texture units of the card by the core clock speed of the chip. The higher 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 number of pixels that the graphics card can possibly write to its local memory in one second - measured in millions of pixels per second. Pixel rate is worked out by multiplying the amount of colour ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel rate also depends on lots of other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to reach the max fill rate.