Compare any two graphics cards:
GeForce GTX 650 vs Radeon HD 6870
IntroThe GeForce GTX 650 comes with a core clock speed of 1058 MHz and a GDDR5 memory frequency of 1250 MHz. It also features a 128-bit bus, and uses a 28 nm design. It features 384 SPUs, 32 TAUs, and 16 ROPs.
Compare all of that to the Radeon HD 6870, which features core clock speeds of 900 MHz on the GPU, and 1050 MHz on the 1024 MB of GDDR5 memory. It features 1120 SPUs as well as 56 Texture Address Units and 32 Rasterization Operator Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
The Radeon HD 6870 should theoretically be quite a bit faster than the GeForce GTX 650 in general. (explain)
Texel RateThe Radeon HD 6870 is quite a bit (about 49%) more effective at anisotropic filtering than the GeForce GTX 650. (explain)
Pixel RateThe Radeon HD 6870 is a lot (about 70%) more effective at full screen anti-aliasing than the GeForce GTX 650, and also should be able to handle higher 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 (measured in megabytes per second) that can be transferred across the external memory interface in a second. It's calculated by multiplying the card's interface width by the speed of its memory. In the case of DDR RAM, it should be multiplied by 2 once again. If DDR5, multiply by ANOTHER 2x. The higher the memory bandwidth, the faster 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 processed per second. This is worked out by multiplying the total number of 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 chip could possibly record to its local memory in a second - measured in millions of pixels per second. The figure is worked out 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 also depends on quite a few other factors, most notably the memory bandwidth of the card - the lower the bandwidth is, the lower the potential to get to the maximum fill rate.