Compare any two graphics cards:
GeForce GTX 650 vs Radeon HD 4890 2GB
IntroThe GeForce GTX 650 features a GPU clock speed of 1058 MHz, and the 2048 MB of GDDR5 RAM is set to run at 1250 MHz through a 128-bit bus. It also is made up of 384 SPUs, 32 Texture Address Units, and 16 Raster Operation Units.
Compare those specs to the Radeon HD 4890 2GB, which features a core clock speed of 1000 MHz and a GDDR5 memory speed of 975 MHz. It also features a 256-bit memory bus, and makes use of a 55 nm design. It features 800(160x5) SPUs, 40 TAUs, and 16 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Performance-wise, the Radeon HD 4890 2GB should in theory be a lot superior to the GeForce GTX 650 in general. (explain)
Texel RateThe Radeon HD 4890 2GB will be a bit (approximately 18%) more effective at anisotropic filtering than the GeForce GTX 650. (explain)
Pixel RateThe GeForce GTX 650 will be a little bit (more or less 6%) more effective at FSAA than the Radeon HD 4890 2GB, and will be capable of handling higher resolutions more effectively. (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 over the external memory interface in a second. It's calculated by multiplying the card's bus width by its memory clock speed. In the case of DDR RAM, the result should be multiplied by 2 again. If DDR5, multiply by ANOTHER 2x. The better the bandwidth is, the better the card will be in general. It especially helps with AA, HDR and higher screen resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that are applied in one second. This is calculated by multiplying the total amount of texture units of the card by the core clock speed of the chip. The better this number, the better the card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels per second.
Pixel Rate: Pixel rate is the maximum amount of pixels the graphics card could possibly record to the local memory in a second - measured in millions of pixels per second. The figure is calculated by multiplying the amount of colour ROPs by the the core clock speed. ROPs (Raster Operations Pipelines - aka Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel output rate is also dependant on lots of other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the ability to get to the maximum fill rate.