Compare any two graphics cards:
GeForce GTX 650 vs Radeon HD 4890 2GB
IntroThe GeForce GTX 650 has a GPU core clock speed of 1058 MHz, and the 2048 MB of GDDR5 memory is set to run at 1250 MHz through a 128-bit bus. It also is comprised of 384 Stream Processors, 32 TAUs, and 16 Raster Operation Units.
Compare those specifications to the Radeon HD 4890 2GB, which features clock speeds of 1000 MHz on the GPU, and 975 MHz on the 2048 MB of GDDR5 memory. It features 800(160x5) SPUs along with 40 Texture Address Units and 16 ROPs.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Performance-wise, the Radeon HD 4890 2GB should theoretically be quite a bit superior to the GeForce GTX 650 in general. (explain)
Texel RateThe Radeon HD 4890 2GB will be a small bit (approximately 18%) more effective at texture filtering than the GeForce GTX 650. (explain)
Pixel RateIf running with lots of anti-aliasing is important to you, then the GeForce GTX 650 is superior to the Radeon HD 4890 2GB, but only just. (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 max amount of information (in units of MB per second) that can be transported across the external memory interface in one second. The number is calculated by multiplying the bus width by its memory speed. In the case of DDR memory, it should be multiplied by 2 again. If it uses DDR5, multiply by ANOTHER 2x. The better the bandwidth is, the faster the card will be in general. It especially helps with AA, High Dynamic Range and higher screen resolutions.
Texel Rate: Texel rate is the maximum texture map elements (texels) that are processed per second. This figure is calculated by multiplying the total amount 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 a second.
Pixel Rate: Pixel rate is the maximum amount of pixels that the graphics card can possibly record to the local memory in a second - measured in millions of pixels per second. The figure is calculated by multiplying the number of Render Output Units by the clock 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 fill rate also depends on quite a few other factors, especially the memory bandwidth - the lower the memory bandwidth is, the lower the ability to get to the maximum fill rate.