Compare any two graphics cards:
GeForce GTX 650 vs Radeon HD 4850 512MB
IntroThe GeForce GTX 650 has a clock frequency of 1058 MHz and a GDDR5 memory speed of 1250 MHz. It also makes use of a 128-bit bus, and makes use of a 28 nm design. It features 384 SPUs, 32 TAUs, and 16 ROPs.
Compare those specifications to the Radeon HD 4850 512MB, which features a clock frequency of 625 MHz and a GDDR3 memory speed of 993 MHz. It also features a 256-bit memory bus, and uses a 55 nm design. It features 800(160x5) SPUs, 40 Texture Address Units, and 16 Raster Operation Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
Theoretically speaking, the GeForce GTX 650 is 26% quicker than the Radeon HD 4850 512MB overall, because of its higher data rate. (explain)
Texel RateThe GeForce GTX 650 will be much (approximately 35%) better at texture filtering than the Radeon HD 4850 512MB. (explain)
Pixel RateIf running with lots of anti-aliasing is important to you, then the GeForce GTX 650 is the winner, by a large margin. (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 (measured in MB per second) that can be transported over the external memory interface within a second. It's worked out by multiplying the card's interface width by the speed of its memory. In the case of DDR type RAM, the result should be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher 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 are processed in one second. This number is worked out by multiplying the total number of texture units of the card by the core clock speed of the chip. The better this number, the better the video card will be at texture filtering (anisotropic filtering - AF). It is measured in millions of texels applied in a second.
Pixel Rate: Pixel rate is the most pixels the video card can possibly write to its local memory in one second - measured in millions of pixels per second. The number is worked out by multiplying the amount of ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - also sometimes called Render Output Units) are responsible for filling the screen with pixels (the image). The actual pixel rate is also dependant on quite a few other factors, most notably the memory bandwidth - the lower the memory bandwidth is, the lower the ability to get to the maximum fill rate.