Compare any two graphics cards:
GeForce GT 640 DDR3 vs Radeon HD 7750
IntroThe GeForce GT 640 DDR3 uses a 28 nm design. nVidia has clocked the core speed at 900 MHz. The DDR3 memory is set to run at a speed of 1782 MHz on this specific model. It features 384 SPUs along with 32 TAUs and 16 ROPs.
Compare that to the Radeon HD 7750, which makes use of a 28 nm design. AMD has set the core speed at 800 MHz. The GDDR5 memory is set to run at a speed of 1125 MHz on this particular model. It features 512 SPUs along with 32 Texture Address Units and 16 Rasterization Operator Units.
Power Usage and Theoretical Benchmarks
Power Consumption (Max TDP)
The Radeon HD 7750 should theoretically perform quite a bit faster than the GeForce GT 640 DDR3 in general. (explain)
Texel RateThe GeForce GT 640 DDR3 will be just a bit (more or less 13%) more effective at texture filtering than the Radeon HD 7750. (explain)
Pixel RateIf running with a high screen resolution is important to you, then the GeForce GT 640 DDR3 is the winner, though only just barely. (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 largest amount of information (counted in MB per second) that can be transported across the external memory interface in a second. The number is calculated by multiplying the card's bus width by its memory clock speed. In the case of DDR RAM, it must be multiplied by 2 once again. If it uses DDR5, multiply by 4 instead. The higher 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 can be processed per second. This figure is worked out by multiplying the total texture units by the core clock speed of the chip. The higher this number, the better the graphics card will be at handling texture filtering (anisotropic filtering - AF). It is measured in millions of texels per second.
Pixel Rate: Pixel rate is the most pixels the graphics card could possibly write to the local memory in a second - measured in millions of pixels per second. The number is calculated by multiplying the number of colour ROPs by the the card's clock speed. ROPs (Raster Operations Pipelines - sometimes also referred to as Render Output Units) are responsible for drawing the pixels (image) on the screen. The actual pixel fill rate also depends on quite a few other factors, most notably the memory bandwidth of the card - the lower the memory bandwidth is, the lower the ability to reach the maximum fill rate.