Compare any two graphics cards:
GeForce GTX 650 vs Radeon HD 7850
IntroThe GeForce GTX 650 features a GPU clock speed of 1058 MHz, and the 2048 MB of GDDR5 memory runs at 1250 MHz through a 128-bit bus. It also is made up of 384 Stream Processors, 32 Texture Address Units, and 16 ROPs.
Compare all that to the Radeon HD 7850, which features a clock speed of 860 MHz and a GDDR5 memory frequency of 1200 MHz. It also uses a 256-bit bus, and makes use of a 28 nm design. It is made up of 1024 SPUs, 64 Texture Address Units, and 32 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically, the Radeon HD 7850 should be a lot faster than the GeForce GTX 650 in general. (explain)
Texel RateThe Radeon HD 7850 is much (more or less 63%) more effective at AF than the GeForce GTX 650. (explain)
Pixel RateThe Radeon HD 7850 is quite a bit (about 63%) faster with regards to full screen anti-aliasing than the GeForce GTX 650, and also 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: Memory bandwidth is the largest amount of information (in units of megabytes per second) that can be transferred over the external memory interface in one second. The number is worked out by multiplying the card's interface width by its memory clock speed. In the case of DDR memory, it should be multiplied by 2 once again. If it uses DDR5, multiply by ANOTHER 2x. The higher the memory bandwidth, 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 amount of texture map elements (texels) that are applied in one second. This number is calculated by multiplying the total number of texture units of the card by the core clock speed of the chip. The better the texel rate, the better the graphics card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels in one second.
Pixel Rate: Pixel rate is the maximum amount of pixels the graphics card could possibly record to its local memory per second - measured in millions of pixels per second. The number is calculated by multiplying the number of Render Output Units by the the core speed of the card. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for outputting the pixels (image) to the screen. The actual pixel fill rate also depends on lots of other factors, especially the memory bandwidth of the card - the lower the bandwidth is, the lower the ability to get to the maximum fill rate.